Red Eyes, Take Warning



"It's the red beady eyes that's a dead giveaway for the evil fellas."

- SpongeBob SquarePants, Nicktoons: Attack of the Toybots

An easy way to tell a villainous (or sinister) character apart from the protagonists, other than giving him/her a Red Right Hand, seems to be making their eyes red. If they don't start out evil, there's a chance they may get Darker and Edgier over time or perform full-blown Face Heel Turn. It's not the same thing as the "red eye" phenomenon in photos, but if cameras could detect evil, these would probably be the first people they'd catch.

In the progressive algorithm of "Oh Crap" with eyes, we have:

Midnight Blue Eyes (usually good but dangerous for other reasons) < Eyes of Gold < Red Eyes, Take Warning < Hellish Pupils < Glowing Eyes of Doom

The title is derived from an old saying among seafaring travelers: "Red sky at morning, sailors take warning", which means that if the sky is red at sunrise, there's bound to be tumultuous weather ahead. The saying ends with: "Red sky at night, sailor's delight."

This has been around so long it's become a Cyclic Trope, probably multiple times, so be warned! With the diversity of Hair Colors and eye colors in anime, it is entirely possible for someone to have red eyes and be completely innocent! Those with glowing red eyes are almost without exception thoroughly evil or, at least, very dangerous. For those who are not evil, red eyes can serve as a marker for their Elemental Powers, typically fire.

Compare Glamour Failure. A subtrope of Technicolor Eyes. May be part of Evil Albino, or averted/subverted by the Heroic Albino. Not to be confused with the film Red Eye or the liquor. Sometimes a part of Burning with Anger.

Anime and Manga

 * Sumire from Venus Versus Virus has red eyes and Hellish Pupils while in her Berserker state.
 * Dragonball Z
 * Freeza and his family all have red eyes, with the older brother, Cooler, combining this with Glowing Eyes of Doom for his Ultimate Form.
 * The Oozaru transformation of the Saiyans, wherein they also get red Glowing Eyes of Doom and go completely berserk.
 * The generally neutral dragon Shenron also has glowing red eyes.
 * Majin Buu also has them in his second and third forms (in this case, combined with Black Eyes of Crazy).
 * Characters possesed by Baby in GT also have flashing red eyes.
 * Digimon Tamers:
 * The main character has red eyes and appears to subvert this trope, since he is the sweetest of them all...until he gets mad and his pupils contract; what follows afterwards is pure Nightmare Fuel material:
 * Green-eyed trickster Impmon is upgraded into red-eyed killer Beelzemon. After he finally leaves The Dark Side, his eyes become green as Beelzemon as well.
 * Motoko Kusanagi of Ghost in the Shell not only has bright red eyes, but chose the color herself. She's a very scary lady, to the point of remarking casually she's familiar with how for perform dental torture.
 * Neon Genesis Evangelion:
 * Angels tend to have red eyes (when they have them at all).
 * Rei Ayanami and Kaworu Nagisa..
 * In episode 18, EVA-01's eyes glow red when the Dummy Plug is activated.
 * In the new Rebuild of Evangelion film, gets double helping of red eyes and Glowing Eyes of Doom just before
 * Fullmetal Alchemist: Played straight with Scar, then later subverted with other Ishbalans who are, for the most part, victims and refugees of the Ishbalan War.
 * Inverted when Al
 * The homunculi and Father are occasionally depicted with glowing red eyes.
 * Hell Girl: Enma Ai, the eponymous Hell Girl herself.
 * Rurouni Kenshin: Makoto Shishio has narrow red eyes. His intro episode is appropriately titled "Devil of Vengeance". Earlier on, though, protagonist Kenshin Himura himself was exhibiting the trope as Hitokiri Battousai until his battle with Saitou Hajime gave him Eyes of Gold, probably to match the prescribed manga coloring.
 * Naruto:
 * Anyone from the Uchiha clan has them when using the Sharingan, but Itachi pretty much always have them on.
 * Used to some degree whenever Naruto uses Kyuubi's chakra and his eyes turn red (with the added bonus of Hellish Pupils), though he is still aware of whose side he's on. When he reaches four tails, his eyes turn into glowing holes, and that's when everyone knows they're screwed.
 * Also, Hidan, whose eyes are rather pinkish, and Kakuzu, who has red scelera.
 * Filler character Ranmaru has red eyes when he's using his unnamed eye jutsu. He's technically not evil, just willing to assist Raiga even if it involves helping him kill people, until he sees the error of his ways.
 * In Death Note:
 * Misa gets these after she receives the Shinigami eyes. The red eyes also show up for other characters who make this "trade", like . In these cases, the red eyes are a stylistic representation of the power for the audience, but it's implied that there's no visual change in-universe. The Live Action Adaptation instead uses Eyes of Gold.
 * Red eyes are also used metaphorically for Light when his Kira persona shines through (i.e. when he's acting particularly diabolical).
 * Subversion: Mai-HiME's Shizuru Fujino has natural red eyes, but is generally a kind and amiable Student Council President...
 * Robot Girl Miyu, from the same series, . In the Elseworld sequel Mai-Otome, she's more of The Obi-Wan, but still has the red eyes.
 * A more straight-up take is trickster villain Nagi, who's an Enigmatic Minion and in Mai-HiME, and the Big Bad himself in Mai-Otome.
 * The Red-Eyes Black Dragon from Yu-Gi-Oh!! is a literal red-eyed monster. And sure enough, it starts out owned by a minor antagonist...but it later is won by one of the good guys and becomes his signature card. Also, in Yu-Gi-Oh! GX, it's the signature card of someone's Super-Powered Evil Side.
 * In the Toei-produced "Season Zero" of Yu-Gi-Oh!, Yami's eyes were red. And bad guys really should take warning, because not only was Yami completely psychotic originally, but anyone who messed with his friends either ended up dead or even crazier than he was.
 * Professor Daitokuji from GX also has red eyes.
 * In Yu-Gi-Oh! 5D's, 's eyes turn red when
 * Placido/Primo has red eyes as well, as does.
 * Shirahime in Kidou Tenshi Angelic Layer has red eyes, which contrast with her cold-coloured snow queen theme and make her look very ominous. Her operator's not evil, but it sure seems to fit with her being beautiful, unapproachable, and kinda scary.
 * In the first Galaxy Angel game, one member of the Quirky Miniboss Squad is actually named Red Eye. Noah (or so we think) also gets these once she performs the Villain Override. And, of course, as a non-villainous example, there's Vanilla, due to her being a Rei Ayanami Expy.
 * Ruby-Eye Shabranigdo, the supreme demon lord and Sealed Evil in a Can from the first season of Slayers. Lina herself has them too, but she's not that evil, honest.
 * While not all of them are evil (plenty of them are vicious, though), red eyes are the key to identifying who's a dragon in Dragonaut: The Resonance.
 * Lucy from Elfen Lied. Cute. Extremely deadly. Thinks all Humans Are Bastards.
 * All the other Diclonii, too, at least in the anime. Well, definitely Mariko. Nana is more debatable -- she's certainly dangerous, being a Diclonius and all, but doesn't seem particularly fond of killing people unless she thinks it's right.
 * Inuyasha
 * Inuyasha's sclera turn red when his Super-Powered Evil Side takes over. They even glow when he's being possessed by Magatsuhi at the same time.
 * Sesshoumaru's sclera also turn red when he's about to transforms into his true form and unleash his full demonic power. This is never a good thing.
 * Subverted with Kirara who was first introduced as a snarling beast with glowing red eyes. Then it's revealed she's a friend of Myouga's and was just trying to protect the bodies of the villagers who had cared for her. She becomes a friend and ally after that.
 * Naraku's eyes are naturally red. As the Big Bad, this is not good from the outset. When they begin to glow, however, true nastiness is about to happen.
 * Subverted with Kagura. Her eyes are a solid red without pupils. Although introduced as a villain, Character Development makes her an Anti-Villain who tries to help Inuyasha's group, supports Sesshoumaru, and who ends up having an Heroic Sacrifice to save Kohaku's life.
 * [[media:054.jpg|Fuuma's]] eyes in the X 1999 anime series are dark red, in contrast to his manga counterpart, whose eyes can best be described as gold-hazel (giving him something of a cat-like appearance). The change in eye color probably has to do with the taken-for-granted aspect of his true nature in the anime series, while the manga builds up much more subtly towards the Wham! Episode and his Face Heel Turn.
 * Dilandau in Vision of Escaflowne has garnet-colored eyes and platinum hair, and he's totally crazy and bloodthirsty. Turns out, his true form, so the hair and eyes are a side effect of the experiments performed on him.
 * In an odd twist, Guu from Haré+Guu has red eyes in her "normal" form, but considering that she's that world's rough equivalent of Cthulhu, it makes sense.
 * Rue/Princess Kraehe from Princess Tutu, though she's more of a Tyke Bomb tragic heroine than a straight villain.
 * Also,, when he's possessed by Raven's blood in the second season...although they're almost more of a pink than a red. Considering the Monster Raven and his servants also have red eyes, it's probably a sign of Raven's blood.
 * In the Hellsing OAV, when Seras Victoria's eyes shift from blue to red (often glowing), expect bodies to hit the floor in numerous pieces. The first Hellsing anime had Victoria's eyes change from blue to red permanently when she first became a vampire.
 * But the character who really takes the cake with this trope is Alucard himself. Especially when he makes his Nightmare Faces. Oh, and if two red eyes aren't scary enough, how about a thousand of them?
 * Sastre, a one-episode (but still formidable) Witch Hunter Robin villain, has red eyes.
 * Ralph Werec from Soukou no Strain takes a different approach: he may not have red pupils, but the whites of his eyes turn pink when he goes crazier than he usually is. The result is very creepy.
 * Mutsumi from Utawarerumono has red eyes (as does Kamyu when ).
 * Shinn Asuka, the (initial) protagonist of Gundam Seed Destiny, has red eyes. He's not evil, per se, but has definite anger issues.
 * A mecha example in this one, Mobile Suit Gundam 00 features this in the Gundams. The primary celestial being units feature green particles, eyes, and clear pieces. The units that are not using the true GN drives feature the same pieces in red. Guess which ones are evil.
 * A subversion is that all celestial being units turn red when they undergo Trans-Am, which means they are serious.
 * Gets rather weird when Trans-Am burst forgets the green and the red and just goes multi-technicolored.
 * The demonic nobleman in The Fantastic Adventures of Unico has reddish eyes in human form. The eyes of any creature that he corrupts or manipulates seem to turn red as well.
 * Demon Eyes Kyo from Samurai Deeper Kyo is the living incarnation of this trope. Even more impressively, he manages to do this and Glowing Eyes of Doom simultaneously. In an interesting subversion, the nature of Kyo's eyes and his connection to the enigmatic Mibu clan become central points to the plot.
 * Evangeline occasionally did this in Negima!?. In the actual Manga, the author prefers Black Eyes for scary characters; black and white isn't quite up to portraying eye colour.
 * Nube from Hell Teacher Nube has red eyes, representative of his vast spiritual power. Also representative of his tendency to make mincemeat out of anyone who threatens his students.
 * Hatsumi from Yami to Boushi to Hon no Tabibito is a subversion. She has red eyes but is one of the more innocent and benevolent characters in the series.
 * In Nausicaa of the Valley of the Wind, the gargantuan, pillbug-like Ohmu's rows and rows and rows of blue eyes shine bright red when they're enraged. Everything in their path is devastated afterwards, and the spores that collect on their bodies expand the Sea of Corruption a little bit more with each stampede.
 * In Crepuscle, having red eyes automatically makes you a vampire (though not all vampires are violent). The main character Lark proves an exception to the rule.
 * from Baccano! has reddish-brown eyes, rather than straight-up red, but they sure as hell look blood red when, and he's prone to combining these with Glowing Eyes of Doom and Slasher Smiles. The Light Novels also bring in Christopher Shouldered, whose defining features are his permanently and severely bloodshot eyes that appear to be almost entirely red, save the iris.
 * In Vampire Knight, the vampires' eyes turn red when they are suffering from blood lust. And Kaname's eyes are just red in general, and he's not exactly the most benign person...
 * Fresh Pretty Cure plays this straight intially and subverts it later. Setsuna Higashi/Eas, a member of the evil organization of Labyrinth, has dark crimson eyes in human form and bright red eyes when transformed.
 * Horo of Spice and Wolf has red eyes, but is usually good-natured. One should tread lightly when her eyes begin to glow in the dark, but not for the usual reasons.
 * Still, this is a girl you shouldn't make angry under any conditions.
 * Contractors in Darker Than Black are usually completely indistinguishable from normal people, but when they use their powers, their eyes glow red.
 * Bleach:
 * In anime episodes 2 and 3, the Hollow form of Orihime's brother had red eyes.
 * In anime episode 9, the hollow Grand Fisher had glowing red eyes.
 * In the anime, Gin's eyes were revealed as red during his fight with Hitsugaya. However, once the manga revealed them to be blue, the anime corrected this, and Gin's eyes were blue ever after.
 * Kariya Jin, the leader of the Bounts, had red eyes.
 * In anime episode 210, after Captain Kensei Muguruma underwent hollowfication, he had glowing red eyes under his mask.
 * Anime episode 214: the hollow that attacks Don Kanonji and Kisuke Urahara and the giant hollow fortress have red eyes.
 * Anime episode 220. Captain Komamura's bankai, a giant samurai warrior, has glowing red eyes.
 * Haine from DOGS Bullets and Carnage. He's not evil, but still pretty dangerous.
 * Prussia from Axis Powers Hetalia has reddish purple eyes. Also, Romania.
 * Evil Prince Xanxus from Katekyo Hitman Reborn has vicious bright red eyes to go with his nasty temper. Seriously, you do not want to piss him off.
 * Rokudo Mukuro, also from Katekyo Hitman Reborn, has one red eye and one blue one, the red one being the one he draws his powers from.
 * An inversion in D.Gray-man: If Allen's cursed left eye turns black with red concentric rings, you should probably start running. However, it's not a matter of running from him - it's because he just spotted an Akuma and you really don't want to be around when there's bullets flying through the air that can make you dissolve.
 * Mirai Nikki: Yuno sports red eyes, and she's, well, Yuno.
 * In Pandora Hearts, Vincent's Mismatched Eyes qualify him for this trope and Eyes of Gold.
 * Break also has redish eye(s) and.
 * gets these when using B-Rabbit's power.
 * is recently revealed to have these.
 * Kurapika from Hunter X Hunter falls into the "dangerous" (though not evil) category...normally polite and reserved, but if his eyes turn red, you'd better hope he's not looking at you.
 * Averted (inverted?) in Code Geass with its two resident albino characters, Mao and the Tianzi. Mao the Evil Albino has pink eyes (which would actually be blue or purple if not for his Geass) and the Tianzi, who is a pretty good girl, has red eyes.
 * Geass itself takes the form of a Red Eye that you don't want to fall victim to.
 * Satoko and her older brother Satoshi, from Higurashi no Naku Koro ni, have red eyes. They subvert this, being very friendly.
 * Saint Seiya: Gemini Saga's eyes turn from a pleasant blue/green to bright red and glowing whenever his evil side takes over. When this happens, it's a good idea to run away very, very fast...unless you have a death wish, are The Hero, or both. His hair changes colour too.
 * The assassin Tongpu in the Cowboy Bebop episode "Pierrot le Fou".
 * Anyone under the effects of the "red eye" drug, as seen in the first episode.
 * Wizard of Oz: Wicked Witch of the West's eyes glow red every time she uses her magic in the 1986 series.
 * Hajime no Ippo: whenever Bryan Hawk lapses into the deepest pits of his Ax Crazy, his eyes, excluding the pupils, become completely, bloody red. They even border on glowing. It definitely helps making his batshit insane personality much more terrifying. In the manga (probably due to a lack of colors, duh), the eyes are black.
 * Punie's mother, Esmerelda, from Dai Mahou Touge has red eyes. She's as evil as her daughter.
 * In Tekkaman Blade, all of the enemy tekkamen had red eyes and red crystals.
 * Black Butler's Sebastian Michaelis has red eyes that are sometimes paired with glowing Hellish Pupils. Despite being a loyal butler to his young master Ciel, he's basically just tenderizing his soul until he's ready to devour it. Sebastian is very much a demon.
 * Subverted with the Undertaker.
 * Natsume from Gakuen Alice has red eyes in the manga, almost as a warning to the fact that he's a flame-caster (and will most likely try to burn you when he's angry at you). Though, in the anime, his eyes are brown.
 * Sailor Moon: Played straight by Black Lady and Galaxia before Sailor Moon 'befriended' her. Beryl's eyes were also red.
 * Hakuouki: glowing red eyes is one of the easiest ways to identify the "failed soldiers" in the series. Well, that and their violent murderous rampages.
 * In the One Piece anime, Nami's eyes are dark red/very reddish brown. While not evil, she steals from anybody and is called a witch at several points.
 * It should be noted, however, that when her crew mates get on her nerves, she has a tendency to transcend this trope all the way to Demon Head.
 * In the Iron Man anime, Dio's eyes briefly turn red when.
 * Crest of the Stars and its sequels have Admiral Spoor, a particularly volatile Blood Knight, who's marked as dangerous by her blood-red eyes. (Her personal flagship is of the same color.)
 * Hanaukyo Maid Tai La Verite episode 7. While the protagonists are exploring an underground tunnel to rescue Cynthia, several of them start acting in a silly manner. Chief Security maid Konoe Tsurugi gets angry at them, draws her sword, and appears to be about to attack them. As she does so, one of her eyes (which is hidden in shadow) glows bright red.
 * In season 1 Beyblade, the antagonist Kai, who betrays his team and steal bitbeasts, has red eyes. Also in season 3, when he is just about to go nuts, we see his eyes glowing red.
 * In Sora no Otoshimono, Ikaros' eyes turning red means she has entered battle mode.
 * TheEnd from Eureka Seven has red pupils - though its eyes are more disturbing because of the way they roll around in their sockets. But, of course,.
 * Silky from Tenshi ni Narumon has red eyes..
 * Kyubey of Puella Magi Madoka Magica. The end of episode 8 combines this with Glowing Eyes of Doom.
 * Double subverted in Murder Princess. Alita and the rest of her family have red eyes, which no one comments on and are presumably normal. When Falis and Alita switch bodies, however, red eyes are the only warning you'll get.
 * In Magical Record Lyrical Nanoha Force, this is played straight (so far?) with Arnage of Huckebein, although it's not very clear if hers are red-red or more pinkish. She combines this with being an Evil Redhead to get Curtains Match the Window. Earlier on, in Sound Stage X, this is also played straight with.
 * Subverted in the original Magical Girl Lyrical Nanoha. Fate Testarossa is introduced as an adversary and an apparent villain, but it quickly becomes apparent that she's the enemy more by circumstance than choice, and she does a Heel Face Turn near the end.
 * Izaya from Durarara has these; they contrast with Shizuo Heiwajima's Eyes of Gold.
 * Played straight with Ardi from Magical X Miracle (YMMV on whether he's a Complete Monster or a Tragic Monster), but partially subverted with Yue, whose one red eye doesn't seem to mark him as any more evil or dangerous than any other high-caliber wizard/politician/scientist (although his Sleazy Politician enemies may beg to differ). . And to those of you interested in characters' backstories, It Got Worse, but that's an entirely different trope.
 * Inner Moka from Rosario to Vampire is an Action Girl who can Curb Stomp Battle just about any monster she meets. Sharp contrast to Outer Moka, who has green eyes and is basically harmless.
 * If Tsukune EVER gains these, run. No if and/or buts about it. It either means he's angry or worse...
 * FLCL:
 * Ninamori has glowing red eyes while possessed by an alien monster in episode 3 "Marquis de Carabas".
 * The giant hand monster in episode 5 "Brittle Bullet" has red "eyes" in its head.
 * Mamimi has glowing red eyes twice while feeding the robot electronic parts and vehicles in episode 6 "FLCLimax".
 * The Big O:
 * "Eyewitness"
 * Police inspector R. (for Robot) Fredrick O'Reilly's eyes glow red just before he rips off his own arm and throws it (and the bomb attached to it) back at the person who shot the bomb at him.
 * The giant construction robot that goes berserk has a single glowing red eye that moves back and forth in its head like a 1970's Battlestar Galactica Cylon.
 * "Hydra". The giant three-headed electrical monster has many red eyes in lines along its head and body.
 * Subverted with Psychic Detective Yakumo. The hero has one red eye, which means he can see the dead. However, it's normally hidden with a contact lens. His father is the inverse: he wears a red contact lens, in sympathy of Yakumo's red eye. However, the main villain  has two red eyes.
 * Diarmuid ua Duibne in Fate/Zero. When, his Eyes of Gold didn't turn red per se, but they did turn all bloodshot to achieve the frightening effect of making his eyes seem to burn like the flames of hell.
 * The original Bubblegum Crisis has an episode titled "Red Eye's" [sic]. Care to guess what color the antagonist's eyes are?
 * The original Bubblegum Crisis has an episode titled "Red Eye's" [sic]. Care to guess what color the antagonist's eyes are?

Comic Books

 * It depends on the artist, but The Joker sometimes has red eyes.
 * Superman, big time. Granted, his eyes nearly always glow red just before he uses his heat vision in any context, but Superman with BIG glowy red eyes and an angry expression fits this trope and means that someone's about to get seriously hurt. Notable examples include For the Man Who Has Everything (to Mongul: "Burn"), "JLA/Avengers" (in his fight against Thor), and "Kingdom Come", where he had to be talked down from murdering the entire UN Assembly in the final chapter. But perhaps his best display is when Darkseid apparently killed Supergirl in the Superman/Batman arc, and Superman, after shedding some tears for his cousin, donned his red eyes of doom and gave Darkseid the beatdown of a lifetime.
 * An example from Superdickery.com.
 * Subverted in Lex Luthor: Man of Steel. Superman is always presented with red eyes, but it's due to Luther's Unreliable Narrator perspective. And the fact that whenever Superman and Lex Luthor are face-to-face with each other, the reason behind Superman's glowing, angry red eyes is usually because Luthor's just done something utterly monstrous and gotten away with it.
 * When Nicole is brainwashed and turned against the protagonists in Archie Comics Sonic the Hedgehog, her eyes change from green to red. Cue major Oh Crap moment for the good guys and a Hero with Bad Publicity moment that continues to torment her long after she was returned to normal.
 * The original version of the Marvel Universe supervillain The Basilisk.
 * Captain America had these at the end of a What If issue. He was pretty pissed at that moment.
 * The Plutonian. Dear god, the Plutonian.
 * In The Brute #1 (February 1975), the titular creature's eyes glow red when a man knocks his friend, Dr. Turner, unconscious. He then kills the man by throwing him against a wall.
 * Donald Duck and his uncle Scrooge McDuck get the red eyes and very scary expressions whenever they get really angry.
 * The Copy Robot in Mega Man issue 4.

Fan Works

 * In Light and Dark The Adventures of Dark Yagami, after Dark becomes king of the Shinigami, most of his 79 eyes are red, except for one that "contained the tiny good part of his sole".
 * The Dark Fic The Terrible Secret of Animal Crossing has a few pictures of with these eyes. Really quite freaky.
 * The Kung Fu Panda fic A Different Lesson uses this to signify a character falling under More Than Mind Control...assuming the reader hasn't figured it out by the time the eyes show up.
 * In Warcraft fanfic Tales of a Warrior, the lead, Keleria, who is already a Berserker, developes these whenever she slips into blood rages.
 * "A shadowy figure slowly opened his red, glowing eyes (they’ve got to be glowing, otherwise we wouldn’t be able to tell if he opened them or not, and they’ve got to be red, because, c’mon, what other color would they glow)"
 * In the webcomic adaptation of Christian Humber Reloaded, the sociopathic mass-murdering protagonist has red eyes.
 * Averted and played straight in My Immortal. Vampires Ebony and Draco either have red eyes or wear red contacts, and are (supposedly) good guys. Played straight in that Vloxemort, the Big Bad of the story, is frequently described as having red eyes.
 * Rescuing Dara averts this trope, with the hero Chivai and both the heroic and villainous Lucarios all having red eyes.
 * Red Cyclone. Sometimes his eyes give out a spark or two when he devises a plan.

Films -- Animated
"Skipper: Glowing red eyes, that's almost never good."
 * Pongo and Perdita from 101 Dalmatians when they are fighting Horace and Jasper in Hell Hall. Cruella De vil's Nightmare Face also counts.
 * AUTO from WALL-E.
 * Spoofed in Monsters vs. Aliens. After being imprisoned by the military merely for being a 49 foot 11 inch monster woman, Susan starts banging on the walls of her prison. The other monsters warn her not to do that, whereupon a huge door opens to reveal a dark interior with two glowing red eyes within...which merely turn out to be the lights on General Monger's Jet Pack.
 * Rudy the Baryonyx from Ice Age 3, although this is more Evil Albino.
 * The Fabrication Machine and all its robot minions in 9|Nine.
 * When the titular Iron Giant's eyes turn red, it's a good idea to remove yourself from the area.
 * Toy Story 2. Emperor Zurg has glowing red eyes.
 * Disney's Aladdin. While Aladdin and the Genie are in the cave, Aladdin taunts the Genie about the limitations on his wish granting abilities to trick him into getting everyone out of the cave without using up a wish. When the Genie gets angry and starts giving a speech, his eyes turn red momentarily.
 * Mrs. Jumbo from Dumbo normally has Blue Eyes like her son, but they turn red during the scene where she goes crazy as a result of several children making fun of Dumbo, resulting in her being tied up by several circus workers and subsequently being dragged away to be locked up in solitary confinement as punishment for being a "mad elephant".
 * In The Thief and the Cobbler, all of the One-Eyes (an evil race that plans to destroy an idyllic Golden Land) have a single, big red eye.
 * In Care Bears Movie II: A New Generation, Dark Heart has red eyes (and hair and clothes) in his human form. When his eyes change color, it clues everyone in that.
 * In Treasure Planet, Silver's cybernetic eye is usually a yellowy-amber-orange-ish colour, but it changes to red when he gets angry/displeased.
 * Lord Shen, the Big Bad of Kung Fu Panda 2, has red eyes, due to him being an albino peacock.
 * The bear at the end of The Fox and the Hound.
 * Zira from The Lion King II.
 * The Leviathan from Atlantis the Lost Empire.
 * Fidget, when he breaks through the window in the beginning of The Great Mouse Detective, has Red Eyes. Ratigan also qualifies during the climax of the film, after his Villainous Breakdown.
 * The Tyrannosaurus Rex from Fantasia.
 * Red, even in his dog form, of All Dogs Go to Heaven.
 * The Penguins of Madagascar: Operation Blowhole provides a lampshaded example when the Julian doll's eyes start glowing red.

Films -- Live Action

 * As well as Sauron in The Lord of the Rings, being a flaming red eyeball himself, the black horses of the Ringwraiths have glowing red eyes.
 * Vampires in Fright Night (1985). Jerry Dandridge and Amy Peterson in their humanoid forms, Jerry Dandridge in bat form, and "Evil" Ed Thompson in wolf form all have red eyes. Hammer Horror vampires often have red -- or rather, very bloodshot -- eyes.
 * In Dreamscape, the wolves chasing the heroes in the final dream sequence.
 * Black Swan: Natalie Portman's Baleful Polymorph.
 * In Who Framed Roger Rabbit?, Eddie Valiant remembers that the toon who killed his brother had "burning red eyes". That toon is later revealed to be.
 * Star Wars: the "Sith eyes" seen on Darths Maul, Sidious, and Vader in the prequels. Maul is shown to have them all the time, but he's not human and his eye color is never seen while he's doing anything but hunting the heroes and fighting. Vader is only seen with them when he's feeling particularly eeheevil, and Sidious is apparently able to turn them off at will. Darth Tyrannus is never seen with them at all.
 * Those are more gold. Chiss eyes are red, though.
 * They are red-rimmed gold; the irises are gold, but they are surrounded by red. Creepy.
 * In the theatrical version of A New Hope, Vader's eye lenses had a dull reddish tint to them due to the materials used. It probably wasn't intentional, due to the fact that later edits removed the reddishness in order to hide David Prowse's eyes better.
 * The Neimoidian Trade Federation representatives in The Phantom Menace have red eyes.
 * Cad Bane from the Clone Wars series is a straight example.
 * Although we never actually get to see their real eyes, the glowing red goggles of the Red Eyes gang in Mystery Men seem to reflect this trope.
 * Most of the Terminators from, well, the Terminator franchise have glowing red eyes, which become even more obvious when only their endoskeletons are showing.
 * It is probably not coincidental that Cameron has blue eyes under the meat...although the third movie features another quite malevolent Terminator similarly equipped.
 * Actually, Cameron's endoskeleton has red eyes. The blue light we saw in some episodes was explained by Josh Friedman: "It's red because at the core, she's a Terminator. Plain and simple. The lens itself is red. There'd never be a reason to change the lens color. I made [the flash] blue in the pilot to indicate she was different but that wasn't to suggest the hardware was blue. No reason for it." Some theorized that the blue eyes were some sort of Resistance Security Encryption Key, considering its use in unlocking access to both the TDE station in the vault (for the Connors) and the TDE complex in the future (for Derek).
 * It's not the eyes, but the robots in I Robot turn on a red chest light when being controlled by the villain. Justified: it's explained that the red light indicates when a robot is downloading a firmware update from US Robotics.
 * Monster X in both forms in Godzilla Final Wars.
 * In Godzilla: Tokyo S.O.S, the title character tries to charbroil Mothra's newly borne twin larvae with his atomic breath. Mothra jumps in front of her children to save them and is promptly set alight for her troubles. She explodes and, at that point, her children's eyes turn from a benevolent blue to a hellish red and they proceed to team-up with Mechagodzilla to beat the hell out of Godzilla.
 * "Do it, Russell! Make sacrifice! Look into the red eye of your god!"
 * One Hour Photo has Robin Williams in a calm dream sequence, but when he opens his eyes,.
 * Popeye and a very late Olive Oyl in The Movie carrying the newly discovered Swee'Pea at the door of Olive's house after being late for a date with Bluto=big trouble. Bluto, seething with anger, sees Popeye, Olive, and the baby through red eyes, pummels Popeye into the ocean below, and, in the next scene, persuades the taxman to tax the prestigious Oyl family into bankruptcy as revenge.
 * Big Bad Dorian Tyrell in The Mask, while wearing the titular item.
 * Mogwai in the Gremlins series when they've eaten after midnight and become evil.
 * Young Sherlock Holmes. When the gargoyle in the shop starts to animate, its eyes glow red.
 * Subverted in Spaceballs. When the baby xenomorph bursts out of John Hurt's chest, it has red eyes, but it immediately goes into its "Michigan J. Frog" number and dances away.
 * Ghostbusters. After Tully is possessed by one of the dog demons, his eyes flash red when he becomes angry. Dana Barrett's eyes also become red after she is possessed.
 * Freddy had them in the second Nightmare On Elm Street, and they were actually pretty cool looking. Subsequent films gave him normal looking ones, though.
 * Albert Wesker in Resident Evil Afterlife.
 * The Hood, the villain of the live action Thunderbirds film, has these when he uses his psychic powers. His heroic niece, Tintin, has Eyes of Gold in contrast, when she uses her powers.
 * The League of Extraordinary Gentlemen. Mina Harker gains red eyes when she lets her inner vampire out.
 * In Judge Dredd, the deadly ABC robot controlled by Rico has glowing red eyes.
 * The HAL 9000 computer in 2001: A Space Odyssey uses cameras with glowing red lenses to watch the crew of the Discovery.
 * The demonic halfbreeds in Constantine.
 * The Matrix. The Sentinel "search and destroy" robots (which threaten the humans in the real world throughout the trilogy) have multiple glowing red eyes.
 * The Wizard of Oz (1939). In the Haunted Forest, Dorothy and her companions see two evil owls and two vultures. All of these birds have glowing red eyes.

Literature

 * Older Than Print: the monster Grendel from the Old English poem Beowulf is described as having glowing red eyes: "on fagne flor feond treddode,/eode yrremod; him of eagum stod/ligge gelicost leoht unfæger" ("Across the decorated floor the fiend trod, went enraged in mind; there stood in his eyes a foul light most like to flame").
 * Hannibal Lecter of The Silence of the Lambs is depicted with maroon (brownish-red) eyes in the books.
 * One of the villains from Madeline L'engle's A Wrinkle in Time is called simply...The Man With Red Eyes.
 * Lord Voldemort from the Harry Potter books (although not in The Films of the Books).
 * Red eyes seem to imply evil thoughts/feelings. Young Tom Riddle's eyes gleam red briefly at a moment when he is extremely greedy, and later, when he has started turning into Voldemort, his eyes become bloody-looking. Also, when Ron is being psychologically tortured by Riddle!Harry-and-Hermione from the horcrux, his eyes flash red for just a second...before he ignores them and shuts them up for good.
 * Notice the formidable chiasmus at the end of Goblet of Fire. Voldemort has red eyes and uses a green Death Ray. Harry Potter has good green eyes, and uses the good red ray (remember the color-coding of laser beams in the original Star Wars trilogy).
 * Captain Hook had light blue eyes, but when he was angry, they would flash red.
 * In JRR Tolkien's The Lord of the Rings, the villain Sauron, while not red-eyed himself, uses a red eye on black as his symbol.
 * In the Twilight novel series, the vampires who drink only human blood have red eyes.
 * The villainous Steerpike of Mervyn Peake's Gormenghast series has dark red eyes.
 * Melisandre from A Song of Ice and Fire is an Evil Redhead as well.
 * The direwolves have red eyes. The ones the Stark children have are not evil, but dangerous indeed.
 * Only Ghost has red eyes, and that's because he's an albino. The other Stark direwolves have yellow, gold, or green eyes.
 * Grand Admiral Thrawn, a nonhuman Chiss who also had blue skin, had solid red eyes that were often said to be glowing. Even when he's solidly the antagonist, he is less evil and more ruthless.
 * Ysanne Isard actually had Mismatched Eyes, one eye being red, the other eye being blue. She's the head of Imperial Intelligence and decidedly evil.
 * The same series has the much more minor villain Zekka Thyne, who has red eyes and Hellish Pupils.
 * And it has two characters who each have a glowing red prosthetic eye. Neither of them are villains. One, Booster Terrick, is a smuggler who does not approve of the pilot his daughter fell in love with. The other, Ton Phanan, is an incredibly sarcastic ex-doctor hiding the fact that his extensive cybernetics cannot replace the future he lost.
 * Chillingworth from The Scarlet Letter.
 * Dracula has red eyes. His houseguest, Jonathan, being British, does not comment on this.
 * Bored of the Rings, a parody of The Lord of the Rings: the Black Riders have "perfectly normal red glowing fires" where their eyes should have been.
 * H.P. Lovecraft's Cthulhu Mythos story The Haunter of the Dark. The titular monster has a red, three-lobed, burning eye.
 * The monstrous alien in John W. Campbell's novella "Who Goes There" has three red eyes.
 * In Robert E. Howard's Conan the Barbarian stories "Shadows in Zamboula" and "Queen of the Black Coast", villainous Evil Sorcerers have red eyes.
 * Ares from the Percy Jackson and The Olympians books actually has fire where his eyes should be. Hestia is an aversion (as mentioned below).
 * Michael Moorcock's The Queen of the Swords. Prince Gaynor the Damned, an evil champion of Chaos, has dead red eyes that blaze in terror and agony.
 * In the original picture book of Mars Needs Moms, Milo's mom (and I think Milo himself) have bright orange-red eyes. It doesn't mean anything but it does make The Reveal of Mom's face a little unnerving.
 * George R. R. Martin's Haviland Tuf short story "A Beast for Norn". The ironfangs of the planet Lyronica are giant vicious wolf-like creatures with huge teeth and sunken red eyes.
 * Subverted in the web-novel Domina. A lot of the demons have red eyes, but since it's optional, they almost certainly chose them to invoke this trope for intimidation.
 * Lin Carter's Thongor of Lemuria stories.
 * The Grakk, a scaly flying lizard-like monster of the jungles of Chush, has cruel, scarlet eyes.
 * The Dragon-Kings, who were the previous rulers of Lemuria before the humans came, have slitted red eyes. They were extremely evil and had great knowledge of sorcery and necromancy.
 * The Gunth, extremely strong beastmen who lived in jungles, had gleaming red eyes.
 * In The Price by Neil Gaiman, the main character realizes that the creature coming for them is the Devil because it has red eyes. While he's looking through night vision goggles.
 * Michael Stackpole's Wolf & Raven short story "Fair Game". The cyberdog that Selene Reece sends after Wolfgang Kies has eyes that look like red starbursts.
 * In R. A. Salvatore's The Legend of Drizzt, the drow have deep red eyes. This trope is carried even further in that Drizzt, one of only two good drow seen in the series, has lavender eyes.
 * The Star Trek TNG novel The Devil's Heart depicts Captain Picard with red eyes while holding the titular Artifact of Doom on the cover.

Live Action TV

 * Star Trek:
 * In Star Trek: Enterprise, the Na'kuhl (or, as they are better known, the "Red Eye Aliens" or "Evil Alien Nazis") all have red eyes, clinching them as candidates for the most evil-looking aliens in the history of fiction.
 * Jake Sisko and, later, Dukat temporarily develop glowing red eyes while possessed by the Pagh Wraiths in Star Trek: Deep Space Nine.
 * Darien Fawkes of The Invisible Man isn't evil, but he's prone to states of psychosis induced by the invisibility-causing gland in his brain; when he starts to flip out, his eyes go red. But when he gets to the point of no return, his eyes turn silver.
 * Battlestar Galactica: Cylons. The single red flashing eye makes up a great deal of the Centurions' and Raiders' intimidation factor. Strangely, the only time we see a humanoid Cylon with red eyes,
 * When the placid "servant race" of Ood in Doctor Who get red eyes, it's a sign that they've either been posessed by a Satan-like being from before the universe began or . Either way, it's bad news.
 * Meanwhile, the only human that "Satan" managed to possess also gained blood-red eyes while the Beast was in control.
 * Far earlier, those possessed by the similarly diabolical Fenric gained blood-red eyes, but only after they had faded from their initial shade of dark green.
 * In the serial Robots of Death, the eponymous robots' eyes are filled with red static when they prepare to kill.
 * Similarly, the Siren from The Curse of the Black Spot turned not only her eyes, but the rest of her projected body from blue to red when anyone got between her and her victims.
 * Randall Flagg in The Stand miniseries.
 * In Merlin, Gaius realises that two visiting nobles are actually evil enchanters as he sees one's eyes flash red in a fit of anger. He really does take warning at the red eyes.
 * Davis Bloome on Smallville gets these.
 * Supernatural: Crossroads Demons. Other demons have similarly evil shades of white, yellow, or black.
 * In Buffy the Vampire Slayer, after Tara is killed, Willow looks up, and her eyes are glowing red. It's even lampshaded/foreshadowed by the episode's title, "Seeing Red".
 * The second Vorlon Ambassador in Babylon 5 has a red light in the "head" of his encounter suit, compared to the original Kosh's green. He's a much, much nastier person.
 * In the original V series, the Visitors' true reptilian forms had red eyes.
 * Buck Rogers in The 25th Century episode "Space Vampire". The Vorvon's eyes glow red when it's using its Mind Control powers on a victim.
 * The Furies in Lost Girl.
 * Mighty Morphin Power Rangers: Goldar's eyes are red and kinda glowy, Lord Zedd's visor is red, and the occasional monster has had red eyes.
 * Mituaki Gamou, the Big Bad of Kamen Rider Fourze, has eyes that often glow red and was initially known as "The Red-Eyed Man" in promotional materials.

Music
"See these eyes so red Red like jungle burning bright Those who feel me near Pull the blinds and change their minds"
 * David Bowie's "Cat People (Putting Out Fire)", written for the 1982 film, has a lovelorn man singing to an object of desire, warning her of the intensity of his need. The first verse establishes that his eyes are usually green, but they become red in the second verse:

Music Videos

 * Gorillaz bassist and Magnificent Bastard Murdoc Niccals used to have one red eye and one black eye. The red eye appears to have turned black in recent pics, which may mean anything or nothing story-wise.

Mythology

 * The eyes of cemetery statue "Black Aggie" are said to glow bright red in the middle of the night, either blinding or killing anyone who looks into them (source). One Urban Legend/Creepypasta talks about a man who stays at a hotel but is told to stay away from a certain room. Out of curiosity, he peeps through a keyhole and sees an apparently normal room, with a woman sitting against a wall. When she moves, he backs away and returns to his room. Later, he tries looking in again, but he can only see something red through the keyhole. Not able to stand the questions any longer, he asks the hotel clerk what's wrong with the room. She tells him that, years ago, a couple died inside, and they tended not to mention it to avoid upsetting guests..
 * The Urban Legend creature known as Mothman is said to have glowing red eyes.

Newspaper Comics

 * Garfield's art style usually doesn't allow for eye colors at all, but the infamous "abandoned house" sequence (beginning here) has a close-up of one of Garfield's eyes in the final strip, red like blood, with the pupil contorted into a spiral as he refuses to accept what he sees.
 * These aren't a constant for any character in Candorville, but can activate and deactivate them at will. The only exception so far is, who gets  either because of his  status or because he's a
 * Al Capp's Lil Abner strip had the Nogoodniks, which were the evil version of the Shmoos. They were a sickly shade of green and had "li'l red eyes". They devoured "good" Shmoos, were the sworn enemies of "hoomanity," and wreaked havoc on Dogpatch.

Tabletop Games

 * Dungeons & Dragons:
 * Most versions of drow or dark elves have red eyes. They are Always Chaotic Evil and the exceptions inevitably have other eye colors such as violet or yellow. They all have red eyes in deep darkness, however. It's part of their darkvision.
 * Interestingly, the original incarnation of drow as presented in the modules in which they made their first appearance were described as having amber or yellow eyes. It was only in later developments that they were described as red-eyed, possible a case of Fanon due to the misconception that the heat radiance of thermal imaging organs (or ultraviolet imaging organs) appear red to normal vision.
 * Some 1st/2nd Edition monsters with red eyes: babau demon, cloaker, cockatrice, guardian daemon, ildriss grue, medusa, nightmare, night hag, tasked slayer genie, yeth hound, the demon lord Juiblex, and the Nehwon god called Hate.
 * Mystaran examples include the gator men, iron gargoyles, saberclaws, werejaguars (in jaguar form), and yowlers.
 * 3rd Edition:
 * Monster Manual: nalfeshnee (Type IV) demon, drow, gorgon,, hell hound, salt mephit, skeleton, wraith, half fiend, lich, lycanthrope in animal form.
 * Creature Collection: Ratmen/Slitheren (all types have red, beady eyes)
 * '"Relics and Rituals''. The Assassin's Senses spell changes the eyes of the character it's cast on to a deep crimson.
 * OA5 Mad Monkey vs. Dragon Claw. The Chaotic Evil vampiric ningyo (mermaids), two Dragon Claw warriors the PCs kill, and the giant Dragon Claw statue after it's animated.
 * OA6 Ronin Challenge. The powerful Lawful Evil Earth Spider and its minions (goblin spiders, giant spiders, and bakemono) all have red eyes.
 * OA7 Test of the Samurai. Bokika Hokio, the Lawful Evil 16th level samurai daimyo of Fochu province, has fiery red eyes and an explosive temper. The krakentua monster also has red eyes.
 * Module X2 Castle Amber. In the Indoor Forest, the master of the Wild Hunt (Andrew David Amber) has glowing red eyes.
 * Basic D&D module O2 Blade of Vengeance. Gorkalk, the great grandfather of the red dragon Khordarg. It may be that all red dragons in Basic D&D had them.
 * Module RA1 Feast of Goblyns
 * When the PCs encountered a barrier made of skeletons, each skeleton had eyes that burned with a cold, red light.
 * A giant skeleton had pinpoints of red light in its eyes.
 * After Radaga's body was possessed by Daglan, she had cold, red light burning in her eyes.
 * Goblyns had glowing red eyes.
 * Greater wolfweres. In all forms except human, their eyes glowed red in the dark.
 * Dark Sun boxed set DSE1 Dragon's Crown.
 * Booklet "Out of the Valley". The PCs' nemesis Avegro appears in dream form with eyes "like pits of crimson flame", and later on, the PCs encounter a ghast with glowing red eyes.
 * Booklet "The Road of Fire". A wraith (undead monster) the PCs meet has glowing red eyes.
 * Dark Sun Monstrous Compendium Appendix: Terrors of the Desert.
 * The dwarven banshee. The pupils of their eyes flicker red as if a flame burns them from within.
 * Greater Fire Elemental. Its eyes glow an intense bright red.
 * The Chaotic Evil Nightmare Beast, one of the most feared monsters on Athas. They have large red eyes that glow in the dark.
 * The Sand Bride is a Chaotic Evil monster that drains Life Energy and has glowing red eyes.
 * The Chaotic Evil So-ut (Rampager) has glowing red eyes.
 * The Neutral Evil T'Chowb has beady red eyes. It can permanently drain a creature's intelligence by touch.
 * Dark Sun Monstrous Compendium Appendix: Terrors Beyond Tyr.
 * The boneclaw baazrag has red eyes that glow in the dark.
 * The Dune Reaper has eerie, luminescent red eyes.
 * The Magma Paraelemental Beast has fiery red eyes.
 * The Obsidian Retriever has six red eyes.
 * Dragon magazine #51 story "A Part of the Game''. A monster that used its Your Heart's Desire ability to lure 12 men to their deaths has "two red eyes burning like coals in a brazier in the Hall of Pain."
 * Al-Qadim boxed set A Dozen and One Adventures. The black idol in Al-Anwhar has two ruby eyes that glint malevolently. If the PCs touch the eyes, they can be Mind Controlled into sacrificing themselves to the idol.
 * The entire ork race in Warhammer 40000 has evil red eyes. The warning part however usually comes from a mountain of weapon wielding green muscle charging you. Besides, the eyes are quite sunken and difficult to see unless you're up close and suicidal.
 * Or unless it's dark. The 3rd edition Ork Codex featured cover art of a greenskin mob charging a trench during a thunderstorm. The Orks in the foreground were well-lit, while all the ones beyond were just hulking shadows with tiny glimmers of red glaring out at you.
 * Stormbringer:
 * The Stormbringer Companion supplement
 * The Golden Icehound has eyes of red demon-fire.
 * Adventure "Hall of Risk". The demon lord Baaleer has burning-red eyes.
 * Adventure "The Crystal of Daerdaerdarth''. The demon guardian Trunchuss has red eyes.
 * Arduin Dungeon #2 The Howling Tower has a deadly steel tiger monster with red eyes.
 * Shadowrun supplements:
 * Paranormal Animals of North America:
 * The Firedrake and Icedrake (both dangerous carnivores) have red, malevolent-looking eyes.
 * The Gyre (Awakened form of the common turkey vulture) has red eyes. It will attack weak or wounded animals, including humans.
 * The Hell Hound has red-rimmed eyes, and the Awakenings sourcebook clarifies that their eyes are fiery red.
 * The Novopossum has red eyes and acidic saliva. It can fight ferociously when it needs to.
 * The Siren (looks like a small pterodactyl) has red eyes. It is a ferocious predator that attacks and kills humans.
 * The Snow Snake has red eyes that glow in the dark and a poison bite that can kill a human being in seconds.
 * Paranormal Animals of Europe:
 * The Kludde is a shapeshifter that uses its powers to weaken and terrify its prey (including humans) before killing them. It has red corneas in all of its forms.
 * The spirit horses ridden by members of the Wild Hunt have red eyes. They can breathe fire and expel a noxious breath that can render an opponent unconscious.
 * Sprawl Sites. An apparent vampire who attacks the PCs with spells has red eyes.
 * Native American Nations Volume 1:
 * When the (evil and insane) toxic Rat shaman Jesse Johns uses magic, his eyes take on a red tinge.
 * The decker Ram's icon in the Matrix is a huge, black-furred humanoid with glaring red eyes.
 * Critters:
 * The chupacabras has large red eyes. It feeds on blood and Essence, attacking metahumans in remote areas with its paralyzing touch.
 * Denver: The City of Shadows boxed set. The decker named Bash has a Matrix icon with gleaming red eyes. He exists in a permanent state of barely suppressed rage.
 * Call of Cthulhu:
 * Deities: Atlach-Nacha (Great Old One), the Haunter of the Dark (avatar of Nyarlathotep), Ithaqua.
 * Monsters: Black Unicorn of Averoigne (Worlds of Cthulhu #3, "Dark Ages Averoigne"), Bunyip (Terror Australis), Necromantic Skeleton (The Asylum and Other Tales - "Black Devil Mountain"), Proto-Shoggoth (The Asylum and Other Tales, "The Asylum"), rats (Masks of Nyarlathotep - Kenya section), Spectral Hunters, The Thing from Between the Planes (The Fungi from Yuggoth), Werewolves (Worlds of Cthulhu magazine #3, adventure "Malevolence").
 * Mayfair's Chill game monsters: Barghest, Ghoul, Hook Thaggis, Spectral Hound, Werewolf (wolf form).
 * GURPS:
 * Fantasy Folk. Minotaurs have the disadvantages Berserk, Bloodlust, Intolerance, and Savage. They're aggressively antisocial and eat other sentient creatures.
 * Conan: Moon of Blood. The swamp devils have eyes as red as coals of living fire, and the chaken (ape men) have flaming red eyes.
 * Role Master:
 * Shadow World campaign setting: Wraiths, Wild Hunt hounds, Zephyr Hound - Fire (glowing red), Demons of the Sixth Pale (glowing red), the Dragonlord Oran Jatar, Black Unicorns, the Heralds of Night and the Dark Gods Orgiana (glowing red), Z'taar (luminous red), and Scalar (luminous red).
 * Star Trek The RPG (FASA) adventure Orion Ruse:
 * The Big Bad Markos Keras has dark red eyes, unusual for an Orion. His servants think they give him supernatural powers. He has a fierce temper, is rash and impetuous, and is likely to try to have the PCs killed.
 * Alien animals called Slethi have teeth that inject a venom that causes intense, immobilizing pain and ultimately leads to death. They also have bright red eyes.
 * Knights of the Dinner Table #168 "Bait & Tackle" section (adventure seeds). In "Puppetmasters", the inhabitants of a small village develop red eyes when they're possessed by demons.
 * Space Gamer Fantasy Gamer magazine #7:
 * Article "Villains Finish First!". The super villain Gloom has blood-red eyes.
 * Article "Barony - A Tale for a Bored Court". In Barony, dwarves are base, evil creatures which have strange red eyes.
 * Paranoia adventure Send in the Clones. The rats in the Sewerworld adventure have beady red eyes.
 * Dangerous Journeys/Mythus, Journeys magazine issue #2. In the adventure "It's Never a Good Day to Die", the evil necromancer Horace Quintell has eyes that burn with an intense redness.
 * Villains and Vigilantes adventure Devil's Domain:
 * On Easter Island a villain has 4 statues with eyes that "smolder evilly red''.
 * The Daven and Abomination demons have red eyes.
 * Witch Hunter: The Invisible World.
 * The monstrous black hounds that roam the English countryside and attack travelers have glowing red eyes.
 * The vampires known as Apotamkin have blood red eyes.

Toys

 * Zigzagged in Bionicle. As a general rule, the color of the eyes can be used as an indication for "good or evil", but you have to ask yourself how the eyes fit with the armor.
 * In the movie Bionicle: Web of Shadows, Toa Vakama inverts this: he has red eyes until he goes over to The Dark Side, at which point, his eyes turn green. His toy, on the other hand, always had green eyes.
 * The evil Roodaka from the same movie had blue eyes as a standard, but when she got really angry, they turned bright orange/red.
 * And naturally, the original Big Bad, Makuta Teridax, also had his trademark red eyes (which he liked to project into shadowy corners), as did many of his brethren, as well as some other villains in the toyline (Krekka, Sidorak, Piraka, Keelerak spiders, etc.). Some, however, eventually substituted orange for red, when the eye colors became Color Coded for Your Convenience. Generally speaking, though, the eye colors of the Bionicle characters were all over the place, especially in the earlier years.

Video Games

 * Dragon Age II: despite the image above, Hawke never gets these. However,
 * Hostile spiders in Minecraft.
 * Akuma from Street Fighter and Ryu under the influence of the Satsui no Hadou. In both cases, their eyes also glow, meaning you're in really big trouble.
 * Albert Wesker of Resident Evil, especially in Code Veronica.
 * In Resident Evil 4, village leader Bitores Mendez has extremely bloodshot eyes that appear red. One of his eyes is a prosthetic, in fact. A straighter example is the cutscene where a Ganado's eyes glow red before the Plaga bursts out of its head.
 * Yurka from Evolution Worlds.
 * In both Bioshock games, the Big Daddies' eyes turn from yellow to red when they see an enemy. When you see those red eyes, you best get out of there. Same goes if you hear "HEUUUUUUUUUUUUUUUUUUNGH!"
 * Most of the protagonists in Disgaea. Lest you think this should be in the Counter-examples section, they're all demons.
 * The exception to this is Adell in the sequel, who is blue-eyed. Amusingly enough, his actual character model in-game is red-eyed as well --
 * The red color could also be the result of his hair being over his eyes in his sprites. Yukimaru also has blue eyes.
 * In The Legend of Zelda series:
 * Ganon usually has glowing, red eyes.
 * Vaati also has red eyes, and he's the Big Bad for three games.
 * Dark Link often has (glowy) red eyes and is always an antagonist.
 * Fire Emblem has a lot of bad guys with glowing red eyes.
 * The turrets in Portal and Portal 2 each have a singular red eye that emits a targeting laser.
 * The epynomous endboss of Skullgirls has these, in addition to markings on her irises that make her pupils appear like the eye sockets of skulls. Aside from her, the trope is played around with with the rest of the cast: Double's Eldritch Abomination form has red eyes befitting of her serving the Skullgirl, while Filia has red eyes, yet is mild-mannered. Painwheel has glowing red eyes as well, but that's largely an effect of her synthetic Skullgirl blood; she's less a villain and more a victim of mind control. In addition, Valentine has red eyes and cross-shaped pupils.
 * Caleb, the undead asskicker and protagonist from the first-person shooter Blood, has permanent, glowing red eyes.
 * Bowser, the main villain from most of the Super Mario Bros. games, has had sinister red eyes since Super Mario Bros. 3.
 * The Shadow Queen in Peach's body occasionally had glowing red eyes.
 * Count Bleck also has red eyes.
 * The Evil Army in Drakengard initially seems to have these, but, later on, cutscenes demonstrate that they are really Mind Control Eyes. The trope is played straight with Manah, the Big Bad. There's a bit of Fridge Logic here in that her identical twin brother has green eyes.
 * Dark Matter from Kirby, with the prominent ones being the Bonus Bosses and
 * It's worth noting that, in all his forms, as well as his Mirror Land counterpart Dark Mind, Dark Matter is nothing but a giant red eye.
 * Castlevania series usually depicts Dracula as having Red Eyes, and in Portrait of Ruin -- the twins Loretta and Stella both have one red eye, and Brauner also has red eyes. . However, other vampires such as Elizabeth Bartelby, Carmilla, etc. aren't shown with red eyes, so it's not a guaranteed Vampiric trait.
 * Soma gets the red eyes in Dawn of Sorrow if he loses himself to his Super-Powered Evil Side.
 * In Half Life, the Gargantuan's eyes would turn from yellow to red when they saw an enemy.
 * Not always red, but Combine soldiers in Half-Life 2 tend to have glowing eyes.
 * To specify, the Overwatch Elite Mooks soldiers have a large red eye, and Overwatch soldiers with shotguns sort of apply, with reddish-orange eyes.
 * They definitely apply; the shotgun wielding Overwatch soldiers are (some of) the most lethal enemies in the game if you stumble across them in close range, so you really should take warning when you see their red eyes bearing down on you.
 * Also, in Half-Life 2 Game Mod Dystopia, Corps have glowing blue eye. Punk heavies have red eyes. Pictures here.
 * Most youkai in Touhou have red eyes, ranging from evil-but-somewhat-harmless Rumia to hugely overpowered oddball Yukari Yakumo, who is not actively evil, but what she is, is very bored and somewhat...playful with people (when she's not sleeping). Also, other creatures, such as vampires like the Scarlet Sisters, sport them. Reisen Udongein Inaba's red eyes can even cause lunacy.
 * Since when did Yukari have red eyes? They always seemed gold or purple...
 * When they first appeared as bosses, Sakuya and Youmu both had red eyes as well; thanks to Art Evolution and playable character status, however, they went from red to dark blue.
 * It has even become usual to depict Sakuya as having blue eyes, but having them turning red when she is about to kick your ass, as is standard for the trope. This is supported by semi-canonical game Scarlet Weather Rhapsody, where Sakuya's sprite's eyes visibly turn red when she uses some of her spellcards.
 * In several cases, Touhou actually subverts this trope. Of note are the rabbits Reisen Udongein Inaba, often portrayed as a mother figure to the other rabbits, and Tewi Inaba, who can be kinda mean but is far from evil and not really dangerous. Although, Reisen's power is an Evil Eye....
 * Heck, even Reimu, the main character, has red eyes. Though there is some controversy as to how she 'deals' with the incidents.
 * Kun Lan in Killer 7, as part of being an Evil Albino.
 * Lieselotte Achenbach, the Enfant Terrible from Arcana Heart, has red eyes and is nicknamed "The Crimson-Eyed Criminal", as she's an emotionally scarred assassin. She also has white hair. She'd fall under Evil Albino if she were just a bit more pale.
 * Also, the Big Bad Mildred when she absorbs the power of the Elementals and becomes an Archangel.
 * Clarice di Lanza, a nun who is also a demon, usually falls under the Eyes Always Shut trope and is, for the most part, good natured...unless you do something to seriously anger her, at which point her eyes open and this trope is in full effect.
 * Colette Brunel from Tales of Symphonia gains red eyes when
 * Kratos Aurion of the same game has them all the time. It could be because he's a Badass, it could be because, or it might just be a case of Curtains Match the Window, since his hair is the exact same shade.
 * Emil Castagnier's eyes go from Green to Red when he activates his Super-Powered Evil Side, Ratatosk Mode, in the sequel. However, this is a subversion, as Ratatosk Mode Emil is more of an Anti-Hero than anything.
 * Jade Curtiss in Tales of the Abyss. His eyes are clearly brown in the anime sequences, but he has his Scary Shiny Glasses to make up for it.
 * If you follow a (hard to find and easy to miss) sidequest, you learn that his eyes aren't naturally red - they turned red as a side-effect of using magical phlebotinum on himself to strongly boost the power of his spells, since his eyes were where his ability to use magic was concentrated. The Scary Shiny Glasses act as a limiting mechanism, preventing all the energy in his eyes from destroying himself and whatever happens to be around him. Red Eyes, Take Warning, indeed.
 * Another example is Duke from Tales of Vesperia. He really isn't evil, per se, but he is . He is, however, a completely unhelpful and self-righteous jackass.
 * In Tales of Graces, it was more of a "Red eye take warning". (Note the singular) You'll notice that Richard has one red eye -  This occasionally glows, but doesn't become pronounced until much later in the game when it's rather obvious that  . However, during the events of Lineage,
 * In Days of Ruin, you have the Mad Scientist Evil Albino Caulder/Stolos.
 * ÜberCharged members of the BLU team in Team Fortress 2 will have glowing red eyes and be completely invulnerable to enemy fire for a brief period.
 * In Star Fox Adventures, the four dinosaurs that pace along each side of the Walled City's central structure and attack you if you draw near, and the one huge dinosaur underground that serves as the boss for that part of the mission, are known collectively as "RedEye".
 * In The World Ends With You, red eyes are an indication that the person is under the influence of Instrumentality. Only the Reapers actually attack, but still, that it's happening to ordinary people is a sign that something's definitely going wrong with Shibuya...
 * The Raving Rabbids have red eyes whenever they snap and start yelling. That is, quite often.
 * In Left 4 Dead, the Witch is distinctive (and sometimes visible only) by her glowing red eyes. Startling her, thus invoking her wrath, is a really bad idea.
 * The Black Phantoms of Demon's Souls have red face orifices, which should tell you that they are much, much more powerful than your enemies up to that point and you should consider going back the way you came.
 * There's also a non-Black Phantom mook in the first non-tutorial level called the Red Eye Knight. Players that don't know what they're getting into often die within seconds of provoking him. Boss in Mook Clothing indeed.
 * If the eyes of the Dragon God boss turn red, start running and don't stop until you're behind a pillar or other large visual obstruction, unless you like the idea of a fist larger than you are smashing you through a granite wall.
 * In Mario & Luigi: Partners In Time, the Shroob, including the Princess, have red eyes.
 * In the first F.E.A.R. game, Alma's eyes were hidden by shadows and her hair, but in Project Origin, they are visible, and glow a dull red.
 * Naoya in Devil Survivor has red eyes. He's about as nice as this trope suggests. They're extra-distinctive in that he's one of the few characters who doesn't invoke Curtains Match the Window.
 * Final Fantasy:
 * Final Fantasy IV:
 * Played with. While Kain does have red eyes, due to his helmet covering the top half of his face, we only see his eye color after his final Face Heel Turn and Good Costume Switch in the sequel.
 * The DS version of the game gives this trait to the Antlion. When its eyes are normal, it counters physical attacks, but when they turn red, magical attacks are countered instead.
 * Adelle from Final Fantasy Tactics A2 had these eyes when she was in Illua's influence. Illua herself has these eyes too, later in the game.
 * In the very first trailer of Final Fantasy Versus XIII from 2006, Noctis' eyes glow red. proceeding him beating the shit out of a group of soldiers (in a rather dark fashion for a Final Fantasy game). The game has been in Vaporware territory ever since and still hasn't come out as of this writing (August 2010). However, Noctis' character design has been changed over the years and his eyes are now...blue. Whether or not the scene from the first trailer will be in the game is a mystery.
 * In Fable, you can get glowing red eyes if you're evil enough.
 * For the orcs in Warcraft, it's one of their defining traits. Drinking the blood of Mannoroth gave them red eyes that glow fiery red when they descend into demonic bloodlust.
 * Evil Overlord Baron Praxis and Villainous Glutton Krew from Jak II Renegade both have red eyes -- or actually, one each. Subverted with the monk Seem, introduced in Jak 3, who is hostile at first, but turns out to be benevolent and becomes an ally.
 * Forte from Mega Man (Bass in the English version) has these.
 * In Mega Man Zero, Copy X has these as just one more sign that he's not quite...right.
 * In Mega Man ZX, this is a common side effect of being under the influence of Model W. Master Albert takes it to the next level by combining it with Black Eyes of Evil.
 * Mass Effect 2 has Shepard, the protagonist, who - if you play him/her as a violent renegade - gets eyes that glow red. This is due to an aftereffect of the Lazarus project: at the start of the game, you are recently brought Back From the Dead and have scars on your face and cybernetic ocular implants. If you play as a Paragon, they heal over time instead. Regardless of the alignment, however, you have an option to purchase an expensive upgrade to you medical bay that permanently heals the scars, after which your Paragon/Renegade actions will stop affecting your face.
 * Pretty much is a warning in "Shadow of the Colossus." The giants' eyes are blue when they're just moving along, but if you see them turn red, it means you either attacked them or they're about to attack you--so watch out!
 * Silver, your Pokémon GSC rival, gets these in the sequel to match his hair. Nevertheless, he's a Jerkass before his Heel Face Turn.
 * On the subject of Pokémon, we have Cipher Admin Nascour, who happens to be Master Albert's predecessor with the whole black sclera red iris schtick. He just happens to be the face of the most evil Pokemon crime syndicate.
 * Ghetsis, a member of Team Plasma from Pokémon Black and White, takes this trope to new extremes - he has one natural red eye, a glowing red monocle, and a red eye printed on each sleeve of his robe.
 * Beedrill, a giant, poisonous, territorial hornet.
 * Ninetails. It can control minds with said eyes. It's also extremely vindictive, going so far as to curse people for 1000 years for daring to grab one of its tails.
 * The Rhyhorn line. While it does not appear to be malicious, Rhyhorn is dumb and prone to charging and Rhydon is smarter, but still destructive.
 * Hydreigon. It's extremely destructive and will attack anything.
 * Mankey and Primeape. They are pretty much constantly in an Unstoppable Rage and will stop at nothing to beat up whatever angered them.
 * Houndoom. The pain caused by the burn from its pungent flame never stops hurting.
 * Murkrow is a thief and is considered a bad omen. Its evolution is pretty much a slothful, merciless, grudge-holding mafia-don.
 * Persian. It fits Cats Are Mean quite well and one of them appears in the anime as a Right-Hand-Cat.
 * Gyarados. Huge, vicious, and very ill tempered, it has destroyed entire cities.
 * Quilava and Typhlosion. If Typhlosion's rage peaks, everything it touches bursts into flames
 * Sneasel is said to be extremely vicious. It drives Pidgey from their nests to eat their eggs. Its evolution, Weavile, is even more devious.
 * The Larvitar line. Larvitar eats an entire mountain to grow and Pupitar's thrashing can topple a mountain. Tyranitar, too, according to various close-up shots. It's a very dangerous and aggressive Tyrannosaurus Rex that can destroy entire landscapes.
 * While Totodile does not appear to be malevolent, it does not realize the strength of its bite, which is bad because it has a tendency to bite or nip anything. Its first evolution, Croconaw, will not let go when it clamps down and its final evolution, Feraligatr, is surprisingly fast and savagely tears its victim up.
 * Cofagrigus is said to turn people into mummies.
 * Genesect. A prehistoric Pokemon. In its time, it was feared as the strongest of hunters. Apparently, Team Plasma makes it even stronger.
 * Zekrom, the legendary thunder dragon. Although it can be used for good or for evil (like most other species), it can be destructive and chaotic in the wrong hands.
 * Red Basculin.
 * Carvanha is a vicious Piranha that evolves into a still vicious, sly shark that can swim over 75 miles per hour and thoroughly tear apart a supertanker.
 * Primal Dialga. And Dialga, Palkia, and (especially) Giratina in general.
 * Gigalith is capable of blowing away a mountain.
 * Seismitoad shoots a paralyzing liquid from its head bumps. It can also smash boulders with one punch.
 * The Axew line. Haxorus is kind but can be relentless when defending territory.
 * In the anime, Mewtwo's eyes occasionally glow red when it uses its Psychic Powers.
 * One villain from Pokemon Ranger: Guardian Signs, is actually named Red Eyes.
 * Tekken 6, Scenario Campaign:  eyes turn red when  . Main result:
 * Devil Jin, the form that Jin transforms into whenever he is fully corrupted by the Devil gene, has glowing red eyes and is not a very nice guy.
 * Jin's father, Kazuya, has a glowing red left eye while his right eye is normal. His role varies from anti-hero to outright villain to anywhere inbetween at different points in the series.
 * In the Soul Series, most notably the first installment, Soul Edge, Hwang in his "no-input " ending returns home, but with devilish red eyes due to prolonged exposure to Soul Edge itself, not forgetting to mention his possessed facial expression that accompanies them well...
 * The various human forms of Lucifer (Louis in his male incarnations) in the Shin Megami Tensei series should partially qualify. One of his eyes are red. And it really is just a warning, given Lucifer's status as more "chaos" than "evil", but it's a distinctive trait worth note.
 * Once you've earned the True Demon ending in Nocturne, your character's eyes turn red.
 * In Splinter Cell Conviction,  have red optics for their sonar goggles.
 * Halo: 343 Guilty Spark's eye turns red when he becomes Rampant. His Eye Beams turn red as well.
 * Psaro the Manslayer from Dragon Quest IV has red eyes, which give him his evil image.
 * In the official Dragon Quest arcade game, Monster Battle Road series, one of the special attacks which features him reveals him with glowing red eyes.
 * The Praetorian Police in City of Heroes: Going Rogue occasionally say this, "Its eyes glowed red. That's all I need to take the safety off."
 * Some of the mechanical Chimeras of Mother 3 have one red eye.
 * The Jitterskull from Ghouls vs. Humans. "The eyes were blacked out and little red circles were added because we all know that red eyes are EVILLLL."
 * Possessed Cybil in ''Silent Hill'.
 * The Fire Clan in Golden Sun games, who show up consistently in the first two games as powerful and dangerous antagonists, . Blados in Dark Dawn is a Card-Carrying Villain with this trope in full effect.
 * Graf Michael Sepperin in Rosenkreuzstilette has these, but he's pretty much a nice guy as well as a Well-Intentioned Extremist.
 * Of course, the warning part takes effect when his red eyes become Glowing Eyes of Doom upon charging forward as bats, as well as in his transformation and One-Winged Angel form.
 * In Adventure Quest Worlds, Chaos Dragonlord Vath's eyes are normally purple, but when his Berserk Button is pressed, causing him to lose his cool after he finds out that the hero freed the dwarves and they are winning against his army, guess what color they turn...
 * In the Killzone series, the Helghast have a "Red eyes" appearance caused by their masks worn in battle, not too differently from the Combine in Half Life 2 Episode 2.
 * Sly Cooper: Dimitri, as seen here:.
 * This is parodied in Tales of Monkey Island from Chapters 1-4 when pirates are so infected by the Pox of LeChuck, they go into Poxed rages and even shout out silly death threats.
 * Dante from Devil May Cry, before he goes to town on Mundus. Twice for Nero in DMC4, the first time when he gains his Devil Trigger, and the second.
 * Metal Sonic, the most famous Red Eyes in the Sonic the Hedgehog series.
 * Sonic 3 and Knuckles's last Act 1 miniboss is called Red Eye. In line with the trope, it is the most elaborate and difficult miniboss in the game.
 * Some monsters in the Monster Hunter franchise have them. The most notable being the Nargacuga, whose eyes turn glowing red when in rage mode.
 * Asura from Asura's Wrath has natural red eyes. When he crawls out of Naraka for the first time, his eyes become glowing holes, but occasionally flash red again when he gets REALLY pissed, and it means you're in trouble.
 * eyes in Star Ocean: The Last Hope start glowing red to foreshadow his upcoming Roaring Rampage of Revenge...which doesn't end well as he unfortunately does it in a barely-armed shuttlecraft and promptly gets.
 * Jake's eyes change to red when he is being controlled by Specter in Ape Escape. Also, Specter's eyes change when he dons the Peak Point Helmet and uses his newly gained augmented intelligence to try and take over the world by changing history.
 * Video Game/Doom. The Spider Mastermind (AKA Spiderdemon) has glowing red eyes. It also has a chaingun that will chop you to pieces if you give it a clear shot at you.
 * in the final boss fight in Prototype 2.
 * in the final boss fight in Prototype 2.

Visual Novels

 * Gilgamesh from Fate/stay night is blond with red eyes, but considering that Gilgamesh is supposed to be from Mesopotamia, it speaks more of a Phenotype Stereotype and this trope than anything else. Also, in the "Heaven's Feel" route of the game, 's Super-Powered Evil Side has red eyes.
 * Not to mention Ilya, who uses Mystic Eyes to immobilize and kidnap the hero (ultimately, though, she's not evil).
 * Caster's use of Mind Control Eyes is an interesting variant -- the whites of the victim's eyes turn red.
 * Lancer has red eyes too, but he isn't evil in most of the storylines, although he initially appears as such.
 * Likewise, his master, Bazett Fraga McRemitz from Fate/Hollow Ataraxia, has naturally red eyes, and she's one of the good guys.
 * The primary theme regarding this appears to be that Servants who possess red eyes typically have varying levels of godhood. For example, Gilgamesh is 2/3 god and Lancer's true identity is a demigod as well. This also appears to apply to Berserker, who is heterochromatic, with one of his eyes being red. However, that may be the result of the Mad-Enhancement that is part and parcel to the berserker class. It is also worth mentioning that Berserker's true identity is also part-god.
 * In Umineko no Naku Koro ni, the Stakes of Purgatory always wear these eyes. Considering that they are Beatrice's furniture, one can guess what happens when they're around...
 * Inverted in Suika. Shinigami have red eyes, but are exclusively the kindest and gentlest people who have died.

Web Animation

 * Maxwell Edison, in an almost disturbingly well-done Flash video of The Beatles' "The Ballad of Maxwell Edison", is depicted with red eyes.

Web Comics
"Buckley: God damn it, c.viper! I swear I am going to face-fuck you with a dump truck!"
 * Darko, the mercenary from The Stupiders has glowing red eyes: .
 * Otherworlders in Miamaska have red eyes and purple sclera. Citizens see this as a threat to their town and take action accordingly.
 * Amity poses no threat, however, so this trope is similarly averted.
 * Dan and Mab's Furry Adventures: Aaryanna, Aniz, Dark Pegasus, Kria, and Regina all have red eyes, and are all pretty evil to varying degrees (Villainy Discretion Shots notwithstanding).
 * In Adventurers, Khrima has solid red eyes. It's an impressive feat of comic-villainy that this makes him look more silly than intimidating.
 * The yellow salamander/lizard-thing from Gunnerkrigg Court. It may not have been evil, per se, but it was certainly dangerous.
 * The "tainted" or Ver'drowendar from Drowtales have red irises; they "have been seeded by a demonic entity".
 * Parson from Erfworld gains red eyes after completing his sword, in a panel that makes him look genuinely frightening for the first time in the series.
 * The Order of the Stick:
 * Sabine's eyes glow red in her true form. There is an early warning of her true nature in this strip, which is before she's revealed to be a fiend. Later, the glowing-red eyes are a hint for the reader that she's shapechanged.
 * Xykon has glowing red eyes too.
 * Also, Loki, god of Flames and Chaos.
 * Abbey, the Badass Anti-Hero protaganist of Gnoph, has red eyes, due to being an albino. She's not evil, but she's definitely dangerous.
 * Marceline from God Mode is described as a "sado-masochistic chain-smoking woman". Which is more or less true.
 * Penny Arcade:
 * Tycho gets these whenever he gets particularly angry or is acting particularly evil, apparently because his body harbors a dark spectre from the world of dreams.
 * Penny Arcade sub-comic Automata. There's something in that time signature and it changes the eyes from the standard blue to...help.
 * Early on in Chasing the Sunset, whenever Leaf's eyes go red, it means he's about to unleash the Furies. Not sure if it persists later.
 * Chess Piece has a number of them, Clockwork being the exception that proves the rule.
 * Played for laughs in Ctrl+Alt+Del, usually; a recent example being when Buckley got Street Fighter IV and grew increasingly frustrated over the computer AI being cheap.


 * Kagerou: when (the aptly-named) Red takes over Kano's body, his eyes turn red. And Red is a psychopathic rapist and murderer.
 * All the vampires in Hanna Is Not a Boy's Name have red or reddish eyes, although some are more evil than others and the least evil of the four we've seen so far isn't drawn with visible irises at all.
 * Valentino, the Big Bad of Marilith, has red eyes. The effect is highlighted by the rest of the strip being mostly in black and white.
 * Werewolves' eyes shift colors in Cry Havoc, mainly to yellow, but also into shades of red when very angry or trying to be threatening.
 * Also, Major Priduex has red eyes, which is comented upon as being unusual.
 * Dr. Schtein of String Theory has prosthetic eyes that glow a sinister red, having lost his original eyes in a lab explosion. Thus far, they seem to be foreshadowing his eventual rise to supervillany.
 * They even glow in the dark, much to the horror of his prison roommate.
 * The visor of Kelelder the Planet Thief's helmet in Jix is red. Earlier in the comic, Pratos the Bounty Hunter's visor was also red, though some time after, it was decided she wasn't a baddie, so she got a new set of armor with a black visor.
 * Dyonus, an android, has red optics, though whether or not he is evil is debatable.
 * In El Goonish Shive, the first time Grace is seen to shapeshift her eyes go red during the transformation. This was dropped during all subsequent transformations.
 * Pibgorn: Dru, when he asks after Pib.
 * Underling: Demons. This is awkward for Lazarus when he gets them, and a tail, and horns.
 * Memoria: Rhino.
 * In Roza, the monstrous guard.
 * In Impure Blood, when annoyed. Note that her eyes can also glow blue for other magical purposes.
 * Johnny K. Gambino.
 * And, ironically, his opposite number, Vladimir Von Helson, via Mismatched Eyes (one gray as is standard for Gaian vampires, one red apparently just for the sake of this trope).
 * In Endstone, rocking the Banestone gives Jon red eyes.
 * Archipelago: when someone makes a deal with the Great Raven, their left eye is turned black with a red pupil.
 * In Wooden Rose, Nessa's "child" has red eyes.
 * In Comic Shorts, Leko the Robot's normally green eyes turn red when he gets very angry.
 * Girl Genius: while subtle, it is seen well in this strip that Mama Gkika has red eyes. Possibly other Jägers, too.
 * The Bongcheon Dong Ghost has red eyes, but by the time you see them, it's already very obvious...and too late.
 * Rescuing Dara averts this trope, with the hero Chivai and both the heroic and villainous Lucarios all having red eyes.

Western Animation

 * Nearly all the Decepticons of the original Transformers. Later versions had a bit more optical variety.
 * Transformers Animated has all red-eyed (or in the case of Soundwave, red-sunglassed) Decepticons like the original cartoon, with the exception of the technically-not-a-Decepticon Swindle, who has purple eyes. However, Sari Sumdac, a human child, also appears to have red eyes. Also, in Animated, Wreck-Gar's eyes turn red when he briefly became a Decepticon due to his Funny Schizophrenia and being incredibly suggestible. An interesting example occurs in Wasp. Originally, he had blue eyes, but after his stay in prison (and subsequent madness and desire to turn   into iron filings), they become purple. And what color do you get when you mix red and blue?
 * eyes also turned red when they were brainwashed by  into being evil.
 * Silverbolt from Beast Wars' optics are normally gold, but when Blackarachnia was killed and he uttered Tarantula's name in a vengeful manner, they turned red.
 * False Convoy in Transformers Return of Convoy is distinguished from Optimus Prime by having red eyes instead of blue.
 * Shattered Glass, of course, reverses this, with the Decepticons mostly having blue optics and the Autobots mostly having red ones. Though there are a fair number of green, yellow, and other oddball optic colors on both sides, and Heatwave strangely has red optics despite being a nice guy, even by his fellow Decepticons' standards.
 * The Affably Evil Emperor Zurg from Buzz Lightyear of Star Command.
 * Also, XR had red eyes during his brief stint as villain NOS-4-A2's vampire slave.
 * Atomic Betty had an episode when Rich Bitch Penelope was cloned and the clone had red eyes. It was probably less evil than the original.
 * The Dark Ace from Storm Hawks.
 * After his army of undead warriors has been halted, the Horned King's eyes go angrily crimson in The Black Cauldron.
 * Skeletor, nemesis of He-Man from He-Man and the Masters of the Universe. In the 2002 version, his eye (sockets) function as a literal warning, as little red lights start growing in them when he gets angry or excited in evil ways.
 * The Legend of Tarzan: the eyes of elephants turn glowing red when they turn rogue.
 * When Thing is brainwashed in an episode of Fantastic Four, his eyes actually turn from blue to red until the effect is reversed.
 * Originally used in Gargoyles for Demona, until the creators decided it would be too obvious and established that it was a feature for all female gargoyles, averting the trope; male eyes, on the other hand, glow white. The scheme is reversed for Gargoyle clones, with males' eyes glowing red and females' glowing white.
 * Darla Dimple in Cats Don't Dance has eyes that flash red when she's feeling particularly insane.
 * Joker in The Batman has nearly completely red eyes (but yellow pupils). His Justice League design (also used for Batman Beyond and Static Shock) also has red pupils sometimes, if you look closely.
 * The red eyes on the latter-day DCAU design, along with the slicked-back hair sported by the Future Joker design in Batman Beyond: Return of the Joker, were inspired by the novel's descriptions of Hannibal Lecter.
 * Zarm from Captain Planet and the Planeteers has his eye turned red when totally angry and when using his More Than Mind Control.
 * Several of Danny Phantom's enemies have red eyes, including his arch-rival, Vlad Plasmius (whose eyes are blue in human form and completely red and pupil-less in ghost-form), and his sociopathic alternate-future self, Dark Danny (AKA Dan Phantom). Red-eyed Dungeon Master Clockwork, on the other hand, despite being originally portrayed as a villain, is good-hearted but on the neutral side.
 * Let's not forget Danny's red eyes when under the control of Freakshow in "Control Freaks".
 * A variation exists in Re Boot; Matrix's gold cybernetic eye's "(V)" pattern begins glowing red when he's about to go into Badass mode. Although Matrix isn't evil, he does have antiheroic tendencies.
 * Trigon in Teen Titans, very bad dude indeed.
 * Brother Blood, Big Bad of the third season, has eyes that glow red when he uses his Psychic Powers; in the fifth season, the mechanical eyes on the skull-"face" on the Brain's life-support pod also glow red when the Brain is interfacing with his computers or is just angry.
 * The Powerpuff Girls (and its anime and comic counterpart) gives us Brick of the Rowdyruff Boys. True to this trope, Brick, while not necessarily evil, does love to cause destruction and hurt others (well, in the show and anime at least, the comic may avert this).
 * In one episode, Professor Utonium had glowing red Mind Control Eyes after Him turned all of his love for the girls into hate.
 * The Grinch in How The Grinch Stole Christmas has red pupils on yellow for most of the film. His eyes turn blue-on-white during his Heel Face Turn, then switch back (by mistake?) for a few shots, then stay blue.
 * Odd variant: while Serpentor from G.I. Joe: A Real American Hero was always evil, his eyes briefly turned red when he held the battleax of Vlad the Impaler, one of the many historical tyrants whose DNA he shared. This was presumably a hint that Vlad had really been a vampire in the show's universe and contact with one of his artifacts had evoked that trait in Serpentor.
 * Ickis from Aaahh Real Monsters has eyes that turn red when he's changing into his badass form.
 * Dick Knubbler's robotic eyes turn red when he gets pissed off in Metalocalypse. Not so much 'evil' as 'Jerkass', but when one works for five Chaotic Neutral musicians that cause destruction wherever they go (by accident, sometimes, even!), it's hard to call oneself 'good'.
 * Squidward, Plankton, and Man Ray from SpongeBob SquarePants.
 * Superfriends 1973/74 episode "Menace of the White Dwarf". The Big Bad, Raven (who acts more like a Comic Book supervillain than any other opponent the Superfriends faced during this season), has red eyes.
 * Jonny Quest TOS episodes:
 * "Monster in the Monastery". The fake yeti have red eyes.
 * "The Robot Spy". The titular opponent has one large red eye.
 * The titular characters in The Herculoids episodes "The Mutoids" and "The Crystaloids".
 * Scooby Doo Where Are You episode "A Gaggle of Galloping Ghosts". The Gypsy Fortune Teller, who turns out to be the episode's Villain in disguise.
 * In the Darkwing Duck episode "Time and Punishment", one sign of Darkwing's transformation into the terrible Dark-Warrior Duck is that his eyes start going red.
 * The Son in the Mortis episodes of The Clone Wars Season 3, combined with black sclera.
 * The New Adventures of Superman:
 * "The Team of Terror". When the villainess Satana concentrates on using her brainwaves to change a plastic cylinder into a monster, her pupils glow red.
 * "The Japanese Sandman". The titular monster (who commits evil acts in return for a black pearl) has red eyes.
 * Discord from My Little Pony Friendship Is Magic.
 * Dr. Julian Robotnik from Sonic Sat AM has a pair of red cybernetic optics that shine like hellish spotlights in the dark.
 * Doctor Hamsterviel from Lilo and Stitch: The Series.
 * On Jimmy Two-Shoes, when Heloise is accused of something in court, she flashes these while asking if anyone thinks she's guilty. Wisely, everyone backs down.

Real Life

 * If the entire white of your eye suddenly becomes red, CALL YOUR LOCAL EMERGENCY NUMBER and get to a hospital specializing in stroke patients IMMEDIATELY. This is a major warning sign of a stroke, especially in people with atrial fibrillation or other heart arrythmias.
 * People with acute conjunctivitis (aka "pink eye") gain red eyes until treatment.
 * Reddning of the sclera (the white of the eye) can be a symptom of many things, commonly:
 * Infection of the eyelashes
 * Ulcers
 * Uveitis
 * Allergies
 * A foregin object in the eye
 * Glaucoma
 * Go to the hospital or call your local emergency number (such as 911) if:
 * Your eye is red after a penetrating injury.
 * You have a headache along with blurred vision or confusion.
 * You are seeing halos around lights.
 * You have nausea and vomiting.
 * Call your health care provider if:
 * Your eyes are red longer than 1-2 days.
 * You have eye pain or vision changes.
 * You take blood thinning medication, like warfarin.
 * You may have an object in your eye.
 * You are very sensitive to light.
 * You have a yellow or greenish discharge from one or both eyes.
 * Having blood pooling in the front of the eyes, a disorder called hyphema, may, in rare cases, cause the person's iris to turn into an arguably beautiful, deep, blood-red color. Hyphema is commonly caused by injury or trauma. It may partially or completely block vision. Hyphema may resolve itself, require medical attention, or it may cause permanent visual impairment. Long term hyphema may cause heterochromia or hemosiderosis, accumulation of iron in the body. However, most of the time, the trauma that caused the hyphema in the first place would also damage the sclera (eye white), causing squick and Eye Scream. Even if the sclera has no visible damage and the blood only pools in the anterior chamber, it can still look extremely unnatural (opaque), causing squick.
 * Vipera berus, the European adder, has red eyes. While they're far from being the most venomous snake, they're the only ones who got all the way to Britain and the Nordic countries.

= Counter-examples =

Anime and Manga

 * Saya, the protagonist of Blood: The Last Vampire and Blood+, is a good-natured vampire out to kill the minions of her Evil Twin, Diva (who, by contrast, has blue eyes). Her eyes are naturally dull red, but they turn bright and glowing red when her vampiric abilities kick in.
 * Also, Saya from Blood-C, however, unlike her predecessors, has Gray Eyes at first.
 * Lina Inverse of the Slayers series is another good-natured, red-eyed protagonist, but she's not above blasting villages to smithereens to save the day.
 * Another partial subversion: Fate Testarossa of Magical Girl Lyrical Nanoha starts out as a Dark Magical Girl and The Rival to Nanoha, but eventually turns over to the side of good and stays there for the next two seasons. It should be noted that.
 * Nanoha has yet another partial subversion in the incarnate Book of Darkness/Reinforce. Still a Weapon of Mass Destruction, of course.
 * And some more from the third season: two of the Quirky Miniboss Squad Numbers, Wendi and Deed, also have red eyes, but eventually, both turn out to be decent people, although Wendi's somewhat mischievous.
 * Mayura Daidouji from Mythical Detective Loki Ragnarok, whose red eyes don't really mean anything. When Loki's eyes change to red, though...
 * Chibi-Usa from Sailor Moon has red eyes due to genetic complications of being a Half-Human Hybrid of a Lunarian and an Earthling.
 * For that matter, Setsuna, a.k.a. Sailor Pluto; this has led to lots of fan speculations about Chibi-Usa's "true" origins. Pluto's dark red eyes are a good match to her weapon/Talisman, the Garnet Orb. In the anime version, Luna has red eyes in her cat form (which made her another candidate for Chibi-Usa's "mother"), although, in the original manga, they are always blue, and the live-action "plushie"-Luna went with the manga version.
 * Hikaru from Magic Knight Rayearth is 100% Genki Girl heroine.
 * Rei Ayanami of Neon Genesis Evangelion. In her case, she's simply an albino. She was intended to be creepy, but not evil. Kaworu Nagisa, on the other hand...well, it's complicated.
 * The creepy factor on Rei backfired so dramatically that there was a significant trend in later anime to have quiet, mysterious girls with red eyes and blue hair.
 * The Kuruta tribe, including the Last of His Kind character Kurapika, from Hunter X Hunter, have these - but only when they get emotionally aroused. The Kurutas were decimated because the color of the "scarlet eyes" was so prized. Kurapika is one of the protagonists, though, and, while occasionally a bit cranky, he's very solidly one of the good guys.
 * But, when his eyes turn red, the best thing you can do is run for your life.Even his own friends were scared of him the first time.It does not help that he Took a Level In Badass in the York Shin arc.
 * Kirika from Noir has these, and she's relatively friendly...even when she's putting a cap in a mark's ass. When they upgrade to Hellish Pupils, though...watch out!
 * Every member of the Royal family in Princess Resurrection has red eyes and blonde hair. They're not exactly evil, per se, but with the family-wide elimination game going on...sometimes, things get hectic.
 * Fullmetal Alchemist:
 * Alphonse Elric's eyes glow red whenever he's conscious.
 * Ishbalans have red or reddish-brown eyes, but are generally victims, not villains, except for Scar. Edward even mentions that his people's prejudice against them is in part based on their red eyes and dark skin.
 * This is an interesting inversion: for the Ishbalans, the blue eyes of the Amestrians seem sinister and terrifying.
 * In Simoun, for one brief moment, one of Aaeru's eyes turns red while she is struggling with an enemy pilot. It never happens again and she remains on the side of good.
 * This is actually because his blood was in her eye.
 * Red-eyed Kurogane of Tsubasa Reservoir Chronicle is introduced as having little regard for human life (slaughtering several guards when they try to attack his princess), but over the course of the story, he ends up being the only main character who hasn't been utilized as some sort of Tyke Bomb with Cloning Blues by the Big Bad (though there was an attempt to get him that failed).
 * Similarly, Yuuko of XxxHolic is usually shown with red eyes, and while she's not evil, she certainly is mysterious (the Cheshire Cat Grin doesn't help). Incidentally, this plus her hairstyle makes her resemble a grown up Enma Ai, leading to more than a few (mostly joking) Epileptic Trees on the matter.
 * In Hellsing TV, Seras's eyes remain red after Alucard changes her into a vampire, but she remains a nice person...or at least tries to.
 * Mew Ichigo from Tokyo Mew Mew has red eyes, but she's the furthest thing from evil. In the anime, her human form has brown eyes, but her Catgirl form always has red.
 * Berii, though...
 * Misty Cornwell in Vandread has red eyes and isn't evil.
 * Ayeka and Sasami from Tenchi Muyo!! both have these, though they appear to just be a mark of royalty. Ayeka's The Ojou more than anything, and Sasami...
 * Horo of Spice and Wolf is a partial subversion. She is a wolf spirit and quite dangerous when provoked. However, she spends most of her time on screen in her cute, mostly-human form, helping Lawrence with his business schemes and lusting after apples.
 * In what may be the ultimate subversion, Kamina from Tengen Toppa Gurren Lagann has red eyes and is the epitome of Determinator heroes,.
 * It is probably meant symbolize his fiery fighting spirit more than anything.
 * It's emphasized early on that Sha Gojyo of Saiyuki has crimson eyes along with hair the same color because he's a half-demon. They are considered to be bad luck, though most of Gojyo's bad luck seems to be directed at himself rather than those around him.
 * Rin from Yes! Precure 5 is perhaps the one character in the series for whom a Face Heel Turn seems least plausible.
 * Yukari-sensei from Azumanga Daioh isn't evil, but if you, she might get very angry. And You wouldn't like her when she's angry.
 * Himeno Awayuki, the Redheaded Hero of Prétear, whose eye color matches her hair color. Not evil, just maybe a bit hot-tempered. (If she does get angry, she gets Glowing Eyes of Doom -- those are a bad sign...) Goh has red eyes in the coloured manga pictures (in the anime, they are closer to brown), but this is likely because red is his signature colour due to his element being fire.
 * Chrono from Chrono Crusade has red eyes in his child-like default form, but he's not evil, despite being a demon. In fact, he's actually one of the sweeter characters in the series (despite his fierce temper). Azmaria also has red eyes, but she also has white hair, which might mean she's albino.
 * However, Chrono's eyes do glow red when he's particularly angry...and that's when you really should start running.
 * Jo from Burst Angel has red eyes, is an awesomely badass Action Girl, and.
 * Mess with Meg, though, and the red eyes really will mean that you should take warning.
 * One more example of red eyes being a consequence of element-based color-coding is Inori from Harukanaru Toki no Naka de (and some of his "successors" from later games in the series); he may have a personality very appropriate for his element, but he is still one of the good guys.
 * Ranka Lee from Macross Frontier has red eyes due to her zentran blood. Brera Sterne could also be considered one since.
 * Teito from 07 Ghost gets brilliant red eyes whenever the Archangel/God Mikhail takes over to protect Teito. While this usually means no good for Teito's attacker as Mikhail possesses god like powers, his only wish is to protect Teito and his friends.
 * Pokémon Special: the Dex Holders typically have eye colors matching their names. Red's eyes are red, as would be expected, but unless you're a Rocket (and maybe if you are), he's the nicest guy you'll ever meet. Ruby may be a bit smug, but he's in the same boat as Red as far as his position on the morality spectrum goes.
 * Ghost in the Shell: The Major's eyes are a deep red, but that doesn't keep her from being incredibly hot.
 * The Kirby anime gives us an interesting example with Metaknight, whose eyes change color with his mood. When they glow red, he's either angry or sensing danger, but he's normally a somewhat-nice guy.
 * Melan of Brigadoon Marin and Melan has red, robotic eyes. He's a powerful fighter, but only when he has to be; his personality is actually quite gentle.
 * Gun X Sword gives us a good example of how an Anti-Hero can complicate this trope: Van pilots a red-eyed mech called Dann, and when you see Dann's eyes flash bright red, you know something scary is going down...but he's generally fighting in the name of the innocent or vulnerable. Van's own eyes are a distinctive red-brown color. While he has sometimes driven away opponents just by glaring at them, the red color of his eyes is MOST noticeable when he is thoughtful, sad, or sympathetic; in other words, when his heart of gold is showing.
 * Hanaukyo Maid Tai La Verite. Yashima Sanae has red pupils and is second in command of the Security Division.
 * The eponymous Soul Eater is a protagonist, but he is infected with the black blood, can be rather cold and cynical, and.
 * Kurenai from Naruto.
 * Izumo and Shura from Blue Exorcist.

Comics

 * Superman. Red eyes just means he is on the brink of unleashing his heat ray - which is a reason to take warning if it is on someone (his entry under examples shows that well enough), but not so much if he has a Mundane Utility in mind.
 * Martian Manhunter.
 * Gambit from the X-Men is not really a traditional hero type, but he has red eyes and is not a villain.
 * Although it has been revealed  and has done  It can better be said he's not usually a villain.
 * Like so many of the X-Men, his alignment will shift Depending on the Writer.
 * The Franco-Belgian comic Sambre plays with this trope: the main character's father and older sister are convinced that red-eyed women (who have blood-red eyes due to a form of hemophilia that makes their irises bleed) are evil and dangerous, because of a very ancient war opposing black and red-eyed people. However, neither Iris nor her daughter Julie, the two red-eyed women that have been introduced for now, are actually evil; and while both of them commit questionable acts (especially Julie, who murders the main character's mother in the very first book), it has more to do with the harsh way they were brought up and less with the color of their eyes, contrary to what the Sambre seem to believe.
 * Despite the series' issues with colorists, Elalyth, the djinn mother of ClanDestine is always depicted with red eyes. She is also described by Adam as infinitely benevolent and did persuade him not to kill at least one villain. Definitely one of the nicer members of the family.
 * The character of Wonder Man in Marvel Comics has red eyes. The trope partially applies, however, because he normally keeps them behind fashionable Ruby colored glasses. Generally speaking, if he's not wearing the glasses and those red eyes are fully visible, means it's time to hit things really, really hard.

Fan Works

 * Soulless shell's hero, Leif Melyamos, has red eyes, which turn black during his One-Winged Angel transformation. To quote a riffer during the MS Ting: "I know this is pointless, but why is it that red is his normal eye colour and black isn't? Isn't the other way round more impressive?"
 * Lusnati Style: the titular character, but (don't worry, it's his last one) has these, which he is sensitive about because they intimidate people. While he is a Badass in the extreme, he's actually an Iron Woobie who's rather nice (unless sarcasm is dangerous to you).

Films -- Animated

 * In Watership Down, the rabbits have dark red eyes, as befits an accurate depiction of their species. The rabbits of, which supplies the main antagonists, are given pale blue eyes. This was a change from the book, which may have been to imply their insular, "unnatural" character.
 * Rocko from The Pebble and the Penguin has red eyes.

Films -- Live Action

 * In Iron Man 2, War Machine's eye lights are red as compared to Iron Man's blue. However, this isn't an indication of being evil as
 * The Last Starfighter. When Centauri appears in his true form at the end of the movie, his eyes are glowing red. Although he's a Con Artist and thus isn't completely a good guy, he is definitely on the good guys' side. By helping Alex Rogan become the titular Last Starfighter, he was directly responsible for the victory over the Ko-Dan Armada and saving the Star league (and indirectly, the Earth as well).
 * In Blade Runner, artificial lifeforms have a red glow to their eyes under certain lights. Depending on who you think the heroes are, this is either a counter example or a subversion.

Literature

 * The Jungle Book: the mongoose Rikki-Tikki-Tavi's eyes turn red when he gets angry.
 * Elric of Melnibone has crimson eyes, a feature that is simply part of his albinism. Not entirely a counter-example, as he is a violent Anti-Hero.
 * The Bloodwrath sufferers in Redwall are good guys. When in the throes of Unstoppable Rage, the whites of their eyes turn red. Lady Cregga Rose Eyes Bloodwraths so much that she has pink eyes all the time.
 * Hestia from the Percy Jackson and The Olympians books has fire where her eyes should be. Unlike Ares (mentioned above), the fire isn't intimidating--it has the effect of a cozy hearth instead.
 * In Terry Pratchett's Discworld stories, the eyes of golems (who aren't particularly villainous) glow an unnerving red.
 * In Mort, Death's glowy eyes change from their usually placid shade of blue to red when he's mad.
 * Nuklear Man of Nuklear Age's eyes were said to "glowed with the fury of hell's flames" in a moment of extreme anger; however, he is a relatively good character at the time, making this a subversion. However, watching out is definitely a good idea at this point. Given his backstory, though, this could indeed be a sort of warning.
 * The Gnalish race in the Star Trek Novel Verse. Grumpy, but definitely not malicious.

Live Action TV

 * It is most famous in the TV version of The Incredible Hulk, but when Banner's eyes turn green, it means he's starting to change into the Hulk and the baddies are in big trouble.
 * In the new Knight Rider, the heroic KITT's "eye" LED's are red, while the violent KARR's are yellow.
 * When Russell T. Davies wrote The Second Coming (2003), he specified that the characters possessed by demons have silver eyes, not red ones. Unfortunately, the Evil People Have Red Eyes cliché was so strong that he had to keep correcting his production staff who automatically assumed they had to create red eyes.
 * In Kamen Rider Kuuga, It's when they turn black that you should run far and fast.
 * Red is, in fact, the color of choice for Kamen Rider eyepieces (though exceptions exist). On the other hand, Evil Knockoff Riders seldom have 'em: Kamen Rider the Next gives the Shocker Riders green eyes, Kamen Rider 555 gives the Riotroopers silver ones, Shadow Moon has green, and so on.
 * Similarly, in Tensou Sentai Goseiger, Gosei Knight's visor is normally red. It turned black while Buredoran was mind-controlling him. Let's not forget that that's a trope too.
 * Mighty Morphin Power Rangers: the Triceratops Dinozord and the Dragonzord both have red eyes. The Dragonzord initially fell into the upper section, but the spell on Tommy was broken. Of course, you still don't want to mess with these two because they're Humongous Mecha. The same goes for their Zyuranger counterparts, Guardian Beast Triceratops and Guardian Beast Dragon Caesar. Most of the Thunderzords and the Tigerzord/Mythical Chi Beast/Warrior Won Tiger has red eyes too, as do the Falconzord/Holy Stealth Beast Tsubasamaru and the Bear Ninjazord.
 * In Power Rangers Samurai, a brainwashed Blue Ranger had blue eyes instead of his normal brown.
 * The Narn race in Babylon 5 have red eyes. All of them, all the time. So, in their case, it's nothing to do with the individual's morals or mood. That said, given that Narn start the series with their default role being "hypocritical, super-angry bullies", there might yet be something symbolic, if not evil.

Tabletop Games

 * In indie RPG Cthulhu Tech, the Migou engineered their humanoid Nazzadi servitors with red eyes specifically so they'd freak out the humans. Of course, it turns out that they're pretty nice guys when out from under the Migou's thumb, and they're living and fighting alongside the humans by the time the game is set.
 * In the grim dark future of Warhammer 40000, red eyepieces for helmets and optics is standard and just as commonly found with Chaos Space Marines as for Imperial troops. Of course, this depends on the overall colour of the armour and the modeler's personal preference.
 * The Salamanders chapter of Space Marines all have red eyes as a result of a genetic quirk, but they're one of the few unambiguously nice guys in the setting. Likewise, the Tau's eyes are red, and they're among the least offensive of the bad guys, if not good guys outright.
 * The Chosen of Battles Sidereals in Exalted all have, as their Caste markings, red-irised eyes. This indicates only their relevant area of Fate -- while they preside over conflicts and have relevant abilities, they're no more likely to be psychopaths than calm masterminds or even pacifistic speakers.
 * Dungeons and Dragons Maztica campaign boxed set. The Chac of southern Maztica have red eyes. However, they are Lawful Neutral and always seek to avoid combat, fighting only if they have no other choice.

Video Games

 * Inverted in Xenosaga. KOS-MOS' eyes are normally red and she is quite powerful like this. However, when her eyes turn blue...
 * Albel Nox from Star Ocean 3, though he, uh...has a bit of a problem of dealing with people. He does start out as a villain, though.
 * A BIT of a problem...? Waking people up by ramming your sword through their pillow where their head used to be moments before counts as a lot more than just "a bit of a problem"...
 * To say nothing of a potential Private Action moment quite past his Heel Face Turn where, while walking around in a serene and peaceful city of sorts, he expresses the barely restrained desire to just snap and start killing left and right so much the city's atmosphere's disturbing him.
 * Final Fantasy:
 * Paine from Final Fantasy X 2. Not evil, just not too big on speech, either.
 * Lulu from Final Fantasy X, too. Although, for a heroic character, she's certainly dark, spooky, and lethal. I guess it's not that uncommon in Spira.
 * Final Fantasy VII:
 * Vincent Valentine has red eyes.
 * In the original game, Tifa looked like she did as well. This could be chalked up to lousy graphics, however, as the Compilation reveals them to be unmistakably brown (or maroon).
 * The Dunmer (or dark elves) in The Elder Scrolls all universally have red eyes. As a race, they're grim, suspicious, and xenophobic, but no more evil than any of the other main races.
 * Oswald from Odin Sphere has a red right eye, which becomes a full-fledged glowy eye of Doom during his shadow knight transformation. Although you still have to fight him as a boss in Mercedes' story, he is one of the game's five main characters and is more of a tragic Anti-Hero than a proper villain.
 * Yuri Hyuga, the hero of the first two Shadow Hearts games, has red eyes in the second game (Covenant). His cousin, the samurai Kurando Inugami, and Saki Inugami (the mother of Kurando and Yuri's aunt) also have red eyes. Supposedly, the members of the Hyuga/Inugami bloodlines who are capable of being Harmonixers (people who can transform into demons/monsters) all share this trait.
 * Subverted by Metis from the chapter "The Answer" of Persona 3: FES. Despite the fact that she has red eyes (and, incidentally, is introduced trying to kill the party), she actually turns out to be quite willing to help them get rid of the Abyss of Time -- . She's also quite protective of her "Sister" Aegis.
 * Also, Team Pet Koromaru's eyes are violently red. He's a total cutie, though (unless you're an enemy or a Shadow. Then, Cerberus comes out...)
 * The Female Main Character from Persona 3 Portable is also another example, even being more cheerful and open than her male counterpart.
 * Medli from The Legend of Zelda the Wind Waker. And given the way the eyes don't change with ambient light -- reflecting as much light while in shadow as they do in broad daylight -- she also has Glowing Eyes of Doom in some scenes. These, added to the game's Deranged Animation, makes her scarier-looking than a great many villains, but that's probably unintentional, and she's sweet enough.
 * Generally speaking, most if not all of Medli's people, the half-human half-bird Rito, have red eyes.
 * Tetra's second conceptual artwork had her with red eyes, but she was eventually given dark blue (borderline black) ones instead.
 * There's also Midna in Twilight Princess: bitchy, sure, but ultimately benign (be wary of her anyway).
 * Kafei is one of many civilians in need of help in Majora's Mask. His blue hair and red eyes indicate...nothing, really, though many have speculated that he's descended from the Sheikah due to...
 * ... the ultimate Legend of Zelda counterexample: blond-haired, red-eyed Sheik, in The Ocarina of Time. He is one of the Sheikah, the warrior race sworn to guard the royal family. Sheik appears throughout the game to assist Link in his quest and is, on the whole, a good guy. (Of course, .)
 * Zelda's caretaker Impa is also a Sheikah, and has red eyes. The Ocarina Hot Amazon version is much younger than the elderly woman she is in other games, but maintains her usual white hair. (This makes her a White-Haired Pretty Girl rather than Heroic Albino, as her skin tone is normal.)
 * Shadow the Hedgehog in the Sonic universe has red eyes. Though he's jumped from world-destroying evil to briefly Anti-Hero before settling into Chaotic Good, his eyes have always been red.
 * When Sonic goes into Super Sonic mode, his eyes turn red as well. Depending on who's writing, he can either be the same Sonic but with super-enhanced powers, or turned more or less evil by the raw power of the Chaos Emeralds (earlier depictions sometimes gave Super Sonic green eyes).
 * When red eyes show up on a good guy in the Fire Emblem series, it usually means there's a dragon in their family tree. Examples include.
 * Rajaion is an odd subversion of this trope; when he is doped up on the feral drug, his eyes glow yellow, but after his sanity is restored, his eyes return to their natural (red) color.
 * You'd think that, when
 * It's worth noting that, when it comes to dragons in FE, it's usually Eyes of Gold you must take warning of, not Red Eyes. This is because Eyes of Gold are a genetic trait of Fire Dragons, who are usually depicted as antagonists in the series. With several noteworthy exceptions (such as Medeus of Fire Emblem Akaneia, an Earth dragon), most other dragons are benevolent and most have Red Eyes.
 * And in Fire Emblem Elibe, the Morphs are described as having Eyes of Gold. Naturally, they're all evil.
 * Rock Howard from the King of Fighters universe (from his debut in Garou: Mark of the Wolves as one of the main characters), son of the late Geese Howard, original KOF Big Bad, is depicted with red eyes in all of his official artwork. However, this is mostly a subversion, because he's surprisingly well adjusted, has a pretty pleasant disposition, and,, was raised by SNK poster boy Terry Bogard.
 * in Ar tonelico, who's also a pseudo-Evil Albino.
 * Ashley, sinister Cute Witch, in Wario Ware.
 * Selvaria, one of The Dragons from Valkyria Chronicles, is one of the coldest and most brutal enemies you could ever face. Plus, she has superpowers since she's a Valkyria. On that note, Valkyria in general seem to have red eyes when their powers are activated.
 * Taokaka of Blaz Blue has Glowing Red Eyes. She's a powerful fighter and is a member of a race descended from a living weapon, but is a goofy, well-meaning, childish, largely harmless Cloudcuckoolander. The closest she comes to having any villainous or threatening traits at all is some rather blatant signs of having Covert Pervert tendencies regarding large breasts.
 * Also, Ragna the Blood Edge. Subverted for two reasons: only one eye is red and, although he is a good guy, he's still pretty dangerous anyway.
 * Also, Rachel Alucard. Yet another subversion; sure, she's extremely powerful, both in-game and in-story,, a vampire, a bit of a Jerkass, and rather manipulative, but she really does mean well. Interestingly enough, she's the reason.
 * The game does have a totally straight example. Robot Girl Nu-13 has a red eye and a red eyepatch. And anyone who has played the game knows that she is one scary psycho  SNK Boss.
 * Not exactly evil, but Kate from Harvest Moon is pretty mean as a child and rude as a teenager. Most of the other red-eyed characters subvert this, though.
 * Irisu from Irisu Syndrome is a cute albino and, as such, has red eyes. However, she's too cute to be evil. Depending on your score, however...
 * In Trauma Center: Under The Knife 2, Heather, who is a good friend and assistant at Caduceus, looks perfectly normal. Atlus gave her red eyes for seemingly no reason other than to invert this trope..
 * Many Pokémon.
 * The Bulbasaur line.
 * Chikorita is docile and the fragrance it gives off crates a cozy, friendly, calming atmosphere. Its first evolution, Bayleef, also has red eyes.
 * The Snivy line. Possibly Emboar and Samurott as well; it's hard to tell.
 * Butterfree.
 * Igglybuff. This is in contrast to its evolutions, winch have Blue Eyes.
 * Absol. It's blamed for natural disasters, but it's only trying to warn people.
 * Umbreon
 * Venonat
 * Ponyta and Rapidash
 * The Pokémon of the Ralts evolutionary line are very loyal and benevolent.
 * Horsea line.
 * Riolu and Lucario
 * Poochyena and Mightyena. Wolf-like Hyenas, they are loyal to a skilled Trainer.
 * Electivire
 * Articuno
 * Dragonair
 * Lugia and Ho-Oh. Lugia stays deep at the bottom of the ocean to avoid hurting people and Ho-Oh brought 3 Pokemon back to life.
 * Raikou, Entei, and Suicune
 * Patrat and Watchog. Weak and common.
 * Munna and Musharna.
 * Leavanny is a quite motherly pokemon.
 * Cottonee and Whimsicott
 * Petilil and Lilligant
 * Yamask
 * One of Meloetta's forms.
 * Jenna in Golden Sun, as her eyes are a weird reddish-maroon color. If you considered any Fire Clan characters to be allies during The Lost Age, they might count here, too.
 * Badass Princess Himi of Yamatai in Golden Sun: Dark Dawn.
 * In Bulletstorm, whenever Ishi's ruthless and brutal robotic personality takes over, his electronic eye turns red.
 * We have Freudia Neuwahl and Pamela Arwig in Rosenkreuzstilette, who both have red eyes. The warning part is inverted with Freu, who's pretty much a nice girl. And Pamela, of course, despite appearing to have an insane look in her eyes, is actually very straightforward and sensible.
 * In Baten Kaitos: Eternal Wings and the Lost Ocean, Lady Melodia, a sugary-sweet Damsel in Distress, has very prominent red eyes. She's also friends with Kalas and helps the party sneak into Alfard..
 * In Mega Man Zero, Fefnir has red eyes. Sure, he's an antagonist and a powerful long range reploid with Blood Knight tendencies, but he's not really malicious. His eye color (like his siblings) is a marker to represent his fire powers.
 * In Mega Man Zero, Fefnir has red eyes. Sure, he's an antagonist and a powerful long range reploid with Blood Knight tendencies, but he's not really malicious. His eye color (like his siblings) is a marker to represent his fire powers.

Visual Novels

 * Arcueid, a True Ancestor vampire from Tsukihime. Her eyes are red, but she's a somewhat ditzy good guy. However, when her eyes do change color -- to gold -- then you'd best take warning, as her Super-Powered Evil Side is just around the corner...
 * In the universe of Tsukihime, red eyes are more of an indication of vampirism than anything. Satsuki gets them when she's vampirized, so do Roa, Wallachia,, and . Arcueid has them naturally...the only exception seems to be Nrvnqsr, and even then, a lot of his familiars do have the red eyes anyway, and he shows them, too, on some particular occasions.
 * In Umineko no Naku Koro ni, Sakutarou,, has red eyes, but he's actually just an adorable little thing.
 * In My Girlfriend is the President Irina may have red eyes but isn't any more threatening than your standard Tsundere.

Web Comics

 * Gunnerkrigg Court:
 * Zeta, AKA Zimmy. Caustic, antisocial, and cursed with uncontrollable reality-warping nightmares. Her most evil action so far is  But her red eyes only appear when she's at peace.
 * Moddey-Dhoo was very friendly for a Black Dog Grim Reaper. His eyes are red and also on fire, alongside his permanent grin and fangs.
 * Dan and Mab's Furry Adventures: Boko De' Marl seems to be the sole exception to the straight examples described above. Then again, seeing as she's had about zilch in terms of actual appearances so far, anything's possible.
 * Bob and George: the author is annoyed.
 * William How from The Dreamer has red-tinged eyes, which are especially prominent in this page.
 * Homestuck:
 * Dave Strider has red eyes which he hides behind a pair of Cool Shades. He's the most arrogant and skilled fighter of the four kids, but he's a good guy through-and-though.
 * Terezi also has red eyes which she hides behind Cool Shades. They aren't revealed until long after she is established as being a friend and ally to the kids.
 * Karkat and Aradia's pupils will be red when they grow up, Karkat's being bright red and Aradia's being more of a dull crimson. Assuming they reach maturity..
 * Jack: the titular Jack has red eyes normally -- it's when they go black that you should be (very) worried.
 * Wapsi Square: Shelly's conscience, shown here, has red eyes to go with her generally creepy appearance, but she is much friendlier than her appearance would suggest.
 * Slightly Damned. Buwaro has red eyes and is just the nicest guy you could ever meet. Rhea said that her best friend used to be Ramirez Bloodeyes, who was named after his red eyes.
 * In Rusty and Co, the wight.
 * In Blue Yonder, the superhero Toad. Whom Maiden Flight comes to for aid, and who goes to great lengths to help and protect her and her brother.
 * Bowser Koopa, Jr. in the homoerotic webcomic Roommates. Whereas the canonical young Jr. is rendered with black beady eyes, the 21-year-old Chivalrous Pervert Jr. has red irises like his father's. But this is also a subversion -- while his eyes are genuinely kind and not at all mean, they are also full of playfulness and seductive mischief.

Web Original

 * In the Whateley Universe, the protagonist Tennyo's eyes often glow red when she's angry. Sparks may also fly off her. Even other superpowered kids at Whateley Academy get intimidated.
 * In the animated web comic-esque Broken Saints series, strip club owner Mars sports a pair of glowing red shades that give this exact effect.
 * In episode 18 of Dragon Ball Abridged, Vegeta pops a blood vessel in rage, causing his eyes to appear this way. Cue Nightmare Fuel.
 * The Angry Video Game Nerd: the Nerd, at 1:20 in this video, courtesy of fan art.
 * Gino Gambino. Justified, too, as his father was Gaia's original Big Bad and played the trope straight.

Western Animation

 * Martian Manhunter, on Justice League.
 * Many Transformers series between G1 and Animated have red eyes split equally between good and bad guys. Examples include most of the Maximals and Sari Sumdac.
 * In Exo Squad, many Neosapiens have red eyes, most notably (and possibly as a subversion), Marsala.
 * Inverted in the Batman the Brave And The Bold episode "Revenge of the Reach!": red eyes mean Jaime -- the good guy -- is in control.
 * The Atom: this 1960's Filmation featured evil Beetle-Men with red eyes, in "Invasion of the Beetle-Men".
 * In Teen Titans, one and a half out of five core Titans have this: Cyborg has one cybernetic red eye, and Raven has red eyes when she's pissed. Actually, sometimes, she has four of them, so the statistics all depend on how you count eyes...Raven got those eyes from her dad, so, as with Inuyasha, it's a sign of her demonic half taking control.
 * Trope averted in Guess with Jess. Willow has red eyes. She happens to be one of the more knowledgeable characters in the show. The characters in the show has eyes of red, green, blue, and yellow. They mean nothing; the show is E/I programming for toddlers and has no villains whatsoever.

Real Life

 * The Red Eyes, Take Warning and Evil Albino tropes are commonly inverted for rats and mice, as depicting such rodents as albino shows they are domesticated, not wild. Such animals' eyes are usually referred to as "pink", or even "ruby", not red, to avoid this trope's usual implication.
 * Sadly, a lot of people still avoid taking rodents with red eyes as pets, no matter how docile and sweet they may be. Some animals will get passed over for weeks or months on account of having red eyes.
 * Guinea pig fans have a name for this coloring: PEW or Pink-Eyed White. However, PEW can also refer to the Hartman breed of guinea pigs, a very uniform shorthaired albino breed created specifically for laboratory research.
 * Characteristic eye color of:
 * Red Eyed Tree Frogs
 * Common Loons
 * Red-eyed Vireos
 * Red eyes on photos, unless you turn on the reduction, of course.
 * Many rabbits have nearly red eyes (true red eyes if they're albino). They're not quite the most ferocious or predatory animals in existence.
 * Marijuana. Next to impossible to overdose, and unless you try to drive on the stuff, unlikely to harm others, yet reddens the eyes faster than its rougher cousin alcohol ever could.