Super Mario (franchise)/Nightmare Fuel



Even Mario has run into his share of frights, as these examples will attest to. Luigi, however, hasn't, because he's too afraid.

Remember, this page is for describing general sources of Nightmare Fuel.

Paper Mario has its own page.

General

 * Several people are terrified by Boos. It's pretty much all boils down to the fact that they only chase you when you're not looking. It only leaves the door open to Fridge Horror.

Super Mario Bros.

 * The first Super Mario Bros. gave us the Minus World, a world no man is intended to go to and has no escape, unless you count drowning to death or the reset button as a method of escape.
 * The castles in the first Super Mario Bros. game for the NES are really, really terrifying. There's just something about them; the lifeless black background, the pointy-looking lava that, for some reason, doesn't move... and that music. THAT MUSIC. Not to mention the fact that some of the castle levels are mazes that will repeat endlessly until TIME RUNS OUT AND YOU DIE. (or until you find the correct path)
 * The famous cave music probably creeped out more than a few kids.
 * The Toads. What, you may ask, the cute little friendly guys with the mushrooms growing on their heads? Yes, them. Specifically, the fact that they've got mushrooms growing on their heads. When a mushroom is growing on another organism, that means the mushroom is eating that other organism. Anyone who's had athlete's foot can tell you that even a small parasitic fungus can be painful, so it follows that a fungus larger than your head growing out of your head would be complete agony. So why are the Toads always so cheerful? Because they're not in control of their own bodies, that's why. The fungus has rooted into their spinal column and is using their bodies as Meat Puppets.

Super Mario Bros. 2

 * The friggin' Hawkmouth in Super Mario Bros. 2 (the one that acts as an end of level gate) scared the crap out of some in the end of World 7-2 when it flew off the wall and tried to chase them!
 * It was even creepier in the original Doki Doki Panic, where it was some sort of tribal mask. Look for it here, labeled (rather accurately) as "Evil Door."
 * And then you get past the door to confront Wart - and the music changes to this creepy, disturbing horror/techno mix that just messes with your concentration while you have to catch vegetables in midair and throw them into Wart's open mouth (as opposed to the other bosses where you just had to hit them with weapons). I couldn't beat him for the first time until finally deciding to mute the sound.
 * Let's not forget Phanto. Creepy pumpkin masks that move REALLY fast and chase you? * shudder*
 * Corrupting SMB 2 leads to some horrifying results.

Super Mario Bros. 3

 * World 8 of Super Mario Bros 3. Apparently, Bowser's home base is Hell itself. The gigantic, discolored hands that drag you down on certain tiles are especially creepy to a small kid.
 * The Angry Sun made some too scared to play past World 2.
 * Some were also afraid of the flames jumping out of the lava in the World 1 mini-fortress.
 * The first fortress in World 7, since the entire place is empty. No enemies whatsoever (barring the boss). Even worse is that one can see where the enemies would be, giving the feel that it was just suddenly abandoned.
 * In the Super Mario All-Stars remake of Super Mario Bros 3, World 5's blue mini-fortress has both a lava floor and a ceiling. It's even more unsettling considering that in SMB 3, lava isn't merely a harmless curtain for the top of a Bottomless Pit; rather, touching it kills you instantly, even if you're Super Mario.
 * Boss Bass from Super Mario Bros 3 and Super Mario 64. Super Mario 3's Boss Bass in particular has this habit of jumping right out of the water, snatching you right off the surface and swallowing you whole in one gulp.

Super Mario World

 * There were people who were terrified of Super Mario World. They frequently abused the pause button in the final battle with Bowser. To clarify; in the final battle, Bowser is seated in a hovercraft which is painted like a clown's face. After Bowser is hit a number of times, he flies forward, so that the screen zooms in on the hovercraft. Push the pause button at the right time, and there is a screen full of clown face.
 * What got to some was Mario/Luigi's death sprite. Maybe they went red/green with shock, but to some, they just looked... odd.
 * The big green bubbles in the Vanilla Ghost House freaked many out a bit. They were large, invincible, and always got in the way, and if even two closed in on you you were screwed.
 * The way secret keyholes grow so huge and then swallow up Mario is just plain freaky. The accompanying music only makes this worse.
 * The Big Boos from Super Mario World gave some fright as a kid, but the Mega Moles... oh GOD!
 * The graphics in Super Mario World. Most of the time, they were gorgeous. But many of the enemy sprites were just wrong. The weird, hunched-over shell-less Koopas, the odd posing and so-smooth-it's-creepy animation of the Charging Chuck, the weird stick legs on the Koopa Kids...not to mention the fact that when you die, it looks like Mario is bleeding from his eyes! Accompanied by a Scare Chord, no less!
 * Another Super Mario World example: the GBA version starts with a Nightmare Fuel-ish intro that ends with a Last-Note Nightmare, as seen here; however, if you beat the game, the result makes up for it.
 * Remember those creepy looking Bowser statues in Bowser's Castle if you took one of the rooms, only to encounter a live jumping one?

Super Mario 64

 * Remember Super Mario 64's piano that grows teeth and tries to eat you? To make it worse, it sounds like someone angrily banging their fists on the piano keys. Much of Mario-related trauma has come from that enemy alone. The Big Boo fights and the music were also something else to be scared of, not to mention the creepy calliope music from the carousel.
 * "Ghosts...don't...DIE! Can you get out of here...alive?"
 * The entry to Lethal Lava Land (remember, that flaming face painting?) was frightening enough to scare you out of the room.
 * Mr. I. No matter where you go or how fast you run, he's always WATCHING YOU.
 * Remember what happened when you ran into a door when you didn't have enough stars to open it? DAH DAH DAH DAAAAAAAH NAH! BWOAR WOAR! HAR! HAR! HAR!
 * The endless staircase at the end of the game, with its chromatic xylophone scales OF DOOM. Try listening to it backwards for extra "fun".
 * THAT FUCKING GIGANTIC UNAGI. To those unfamiliar, it was a huge eel with a freaky face, topped with the fact that he doesn't look quite that big at first.
 * Bowser himself. It's just the way his model looks, always with that evil look on his face, and if anything, the polygon look just made him scarier.
 * Bubba Bubba, the giant fish (with Kamina shades!) that eats you on Tiny-Huge Island. It's killable through a glitch, though.
 * The poisonous gas maze in Hazy Maze Cave. Getting bullet spammed by the Snufit wearing A GAS MASK didn't help.
 * The flying books in Big Boo's Haunt as well as the chairs, the wind thing on Tall Tall Mountain, the Bullies that pushed you into lava, and, oh yes, that GIANT FREAKIN' FREIGHT TRAIN-MONSTER that is the Chain Chomp. Shigeru Miyamoto designed Chain Chomps based on his own fears of being bitten by dogs. Thanks, Miyamoto, for making sure your own nightmares fuel other people's nightmares.
 * The only truly scary parts would have to be Eyerok, the Shifting Sand Land boss. The two big-ass rock hands with eyes on the palms. The ones that try to push you off the slender platform and into a pitch black emptiness. And another mention goes to Dorrie, the plesiosaur from Hazy Maze Cave. The big blue dinosaur with the red slit mouth and tiny eyes that a nearby sign claims that will eat you. Thankfully turned into Nightmare Retardant in Super Mario 64 DS with the addition of swim goggles, as well as making his face more Yoshi-like.
 * Mentioning the Eel without Mario's drowning animation in general? Drown and Mario 64 suddenly feels far more graphic than most Gorn games, with Mario desperately struggling and seemingly making failed attempts to gasp for air in blind panic and agony, with the game fading out as Mario's corpse is going limp. The poison gas death (the area mentioned above) is no better, with Mario grabbing for his throat, then falling on the floor with the screen fading out as he lies twitching (apparently still alive) in his final moments on the floor. The toxic area was really the worst in that, as anytime you are breathing it Mario would cough and slowly choke as if struggling for air.
 * Playing with Gameshark in Mario 64 can get you very disturbing results. This video, one of the many that refers to Gamesharking in Mario 64, leads the watcher to ultimate nightmare, especially as Mario enters the castle lobby.
 * The painful cry Mario did whenever he got hurt in Mario 64.
 * In Super Mario 64 DS, if you play as Luigi and turn invisible in a Mirror room on the third floor, you can go through the door that is supposedly the reflection of the entrance door. Going in there, you find yourself in a white abyss with nothing but you, the door, and.
 * The sunken city in Wet Dry World, along with the background to the level (A city of flat-roofed buildings). Completely deserted excluding a lone Bob-omb. What exactly happened there?
 * This one is a long shot, but if you think about it, the main HUB itself could be creepy if you think about it. You're in a big castle/mansion.....all alone....except for the Toads.
 * Hey, remember when you got the Power Star from atop Bowser's submarine, the sub disappeared from Dire Dire Docks for stars 2-6? And that Bowser door opened underwater....becoming a big black hole that SUCKED YOU IN if you got near it???
 * So you just got the 8 stars needed to open the first Star Door. You go through it into a hallway, and at the end is a portrait of Peach. Her face changes as you walk forward, getting more frightened as you walk down.
 * The secret under the moat. It takes place in a gigantic room that is 95% nothingness, with the level itself taking place along the edge.

Super Mario Sunshine

 * Super Mario Sunshine, an otherwise rather bright game, features a level where you have to go underwater (thus, making it a Timed Mission), and clean the teeth of a giant eel; complete with poisonous bubbles and a whirlpool that threatens to suck you in.
 * The Gooper Blooper battles from Super Mario Sunshine. Mario is fighting a giant squid who uses his tentacles and ink that summons slimy enemies to attack. The method of defeating him is to jump on each of his tentacles and graphically pull them off one by one; after doing so, the pulled tentacle will wriggle wildy before disappearing.
 * Phantamanta is a pretty frightening boss, and a pain to beat as well. Its a borderline Eldritch Abomination that can move over ANY surface like some kind of shadow and leaves a trail electric goo, and when you spray it, it splits up, spray them and they split up, spray THEM and they split up! Then, once you got it into its SIXTY-FOUR parts, they all turn red and charge at you like mad!

New Super Mario Bros.

 * New Super Mario Bros. has Bowser fall into lava in the first world. Not much different from what happened at the end of every single castle in the original Super Mario Bros... until the game proceeds to show him desperately flailing in the lava, yelling in agony, and emerging with all of his flesh melted off. Totally unexpected and freaky as all get-out.
 * Mario's next line, immediately after the whole debacle? "That'sa so nice!" What.

Super Mario Galaxy

 * The giant caterpillar in the Gusty Garden Galaxy of Super Mario Galaxy. The way it's almost realistic in appearance in a game with an intensely cartoony art style creates an effect similar to the Uncanny Valley, and it makes some genuinely disconcerting high-pitched noises. The enormous nose and buck teeth do little to diminish this.
 * Speaking of Galaxy, how freaking disturbing it is to see Mario's hand rise up when he sinks in sand or toxic waste, all while hearing him drown?
 * Not to mention that when Mario touches dark matter, he slowly disintegrates, and his life bar isn't empty until AFTER Mario is completely gone. He feels the whole thing!
 * And then there's dying of electrocution, which leaves only a skeleton.
 * Here is a video of a few of Mario's Galaxy deaths.
 * The Gringills in the Beach Bowl Galaxy. The giant ones with googly eyes and teeth almost as long as their head.
 * What about those hovering, screeching Cluckbooms? There is just something vaguely disturbing about them...
 * The Bonefin Galaxy, home to the giant skeletal shark known as Kingfin.
 * The giant jellyfish. Sure, there were only two, but each one was in an rather off-putting location: the first in the Bigmouth Galaxy, where more and more ghosts kept popping out of nowhere underwater, and the second in the Deep Dark Galaxy, where you HAD to swim RIGHT PAST IT because it took up most of a certain passage. (Oh, and both galaxies had some of the most ominous-sounding music in the game.)
 * Also in the Deep Dark Galaxy is a planet accessible by a cannon, which is basically a tiny version of the first planet in Gateway Galaxy. It's kind of odd in the first place to come across something like this, but if you jump on a nearby screw and spin around, the planet will deflate like a giant beach ball. It even rewards you for doing this with coins!
 * Between them, Mario and Bowser wind up destroying the universe.
 * Bowser planned on destroying the universe all along... so that he could remake it as his own glorious empire. Damn. So much for Villain Decay.
 * The music that plays when you wake up the Dino Pirahna is very unsettling, as is the fact that you are on a small planet with the possibility of being plowed into by a giant, blind beast. The Dino Pirahna itself is no better, especially when you get it angry. And when you defeat it, the idea of having just killed a baby doesn't sit right either.
 * Also, when Dino Piranha dies, it's red skin turns a pale purple. Anyone who knows anything about babies or humans in general knows that skin turning blue is not supposed to happen.
 * In in one of the later areas you come across I mean, the guy was freaky enough the first time around, but,
 * Anyone else think poor Luigi's deaths in SMG are a bit Nightmarish? I felt physically sick listening to poor Luigi sob hysterically as he fell to his death. But maybe it's just me...
 * Also, right before Bouldergeist explodes, his uvula pulsates, his head shrinks, and his eyes triple in size... and he explodes...
 * The NPC bees are cute, but take a close-up look at their faces...
 * The Lumas' cycle of gorging themselves, and then committing suicide by exploding into a new celestial object. They are eventually being reborn somehow, but these guys are happy that they are exploding.

Super Mario Galaxy 2

 * Cosmic clones in Super Mario Galaxy 2. The ones in the previous game were simple Mario and Luigi clones that served as racing opponents. In this game, It Got Worse. They follow your every action with a delay of a second or two. If one catches up to you or you bump into one, it hurts. You can't stop for even a quick breather or you'll get hit. And they keep coming. More and more of them get spawned every few seconds, leading to a seemingly endless chain of them. Even the nearby signs are afraid of what they can do. And worst of all, their corruption extends as far as ...
 * Not sure if this makes it better or worse, but... they don't technically hunt down the person they imitate. They mimic their movements perfectly, a few seconds after they do. You touch someone on the shoulder, they touch them seconds later. You pick something up, they mime picking it up themselves. And if you stand still, they collide with you, exploding into dark energy at point-blank range. And until you, or possibly somebody else the comet is focusing on, finishes an arbitrary task, they spawn forever. Following you everywhere. And when you think about it, aren't the other comets also Fridge Horror? Just think of what happens when, say, the Red Comet gives one arbitrary person a time limit to do one task before dying.
 * In several late levels, giant lava monsters suddenly rise up from out of nowhere and engulf your platform in their mouths. The last one is particularly memorable.
 * In one galaxy, a group of penguins are out swimming, watched over by a couple of larger penguins. To get the non-secret star in that stage, you must hit a switch that causes the entire area to freeze solid. It's not just the surface; you can see them under the ice, frozen in midstroke.
 * In the Shiverburn Galaxy, if you change the camera to first-person mode and look toward the cliffs above you, there seems to be three mysterious shadowy figures on the cliff, watching you, and following you. You can read about it here.
 * This shit. This shit right here.
 * They're supposed to be trees. It doesn't help though, because they don't look at all like trees. And they have glowing eyes. Brrr.
 * The file names? "BeyondHellValleySky is where they reside, and HellValleySkyTree is the names, the ominousness of the trees were enough, but those names make them worse.
 * The swirling spirits in the background in the ghost levels.
 * Magmaarghs (a much larger version of Blarggs from Super Mario World). They're huge, hideous creatures made of lava who look incredibly deranged, with strange eyes and huge mouths, and when they try to collapse into Mario or Luigi, they make a very disturbing roar until they lose their form in the lava.

Super Mario 3D Land

 * An Easter Egg: In the yard at the end of any ghost house, waiting long enough causes a ghostly figure to appear in the background just behind the fence and will vanish after a few seconds. This figure doesn't actually do anything and cannot be interacted with, but what makes it creepy is that the thing resembles the Shiverburn Galaxy figures. They're not trees. They're still watching. And they're getting closer.

Misc. Games

 * The Thwomps from Bowser's Castle in Mario Kart 64, its that disturbing Evil Laugh, the green one in the cell is scarier for some reason. Luckily, they aren't scary in the Wii versions remake.
 * The final stage of Tetris Attack for the SNES, where a Godzilla-sized Bowser rises out of a chasm at the end of a mountainside cave. Cue the sinister organ music.
 * The infamous Hotel Mario had some rather unnerving music.
 * Mario Teaches Typing 2, like Mario 64, featured the floating disembodied head of Mario. Unlike the Mario 64 version, this one goes back and forth between cracking jokes and being amusing, to being just plain unsettling at times.
 * The GBA puzzle game Mario vs. Donkey Kong features a relatively realistic 3D rendering of Mario facing off against cartoony Thwomps and Shy Guys, and is brought up at this point in the page due to its Galaxy-like series of disturbing death animations. The default animation (for example, stepping on spikes or touching a Shy Guy from the side) has Mario tilt briefly before he falls face-first into the floor (or spikes!) and stops moving. Then there's the specialty animations for dying to a fiery or electrical attack, which don't pull any punches about how terrifyingly painful it must be for poor Mario.
 * There are three different "death" tracks in the game's BGM. The current (at the time of this writing) comment for the linked video states "Lemme guess, the first is for getting hit by an enemy or obstacle, the second is for running out of time and the third is for falling from a really high place". Which is partially true, but there's more to it. While the first two apply for "standard" deaths (the second, if I recall correctly, is used for getting burnt by lava), the third is used for the most horrifyingly painful and gruesome (for Mario standards, that is) death animations, such as getting squished by a Thwomp, falling from a high place (with Mario falling on his head as a result) and, last but not least, getting electrocuted to death. In fact, you can tell the various deaths apart by listening to the different pitches of Mario's variants of his classic "Mamma mia!". The first is "standard", the second is "exhausted", and the third is "a mixture of pain and horror".
 * In Mario Power Tennis, when Yoshi wins a trophy, there's an animation in which Luigi brings it to him. Things go awry, and in the end Yoshi has swallowed Luigi. He doesn't get spit out. There isn't even an egg. He never escapes.
 * The end of Mario Is Missing, when Bowser is defeated, may scare some young children. You don't fight him, he comes out of nowhere and is shot out of a canon, innocent enough. It's cartoony. Then he falls into the ice, freezes up, is covered in snow, then shatters.
 * In Super Mario Strikers, we have Bowser, who is protrayed as a giant implacable koopa who wreaks major havoc on the field with shells and bombs whenever the "Bowser Attack" options is on instead of comic relief. When that occurs, his entrance would be accompanied with a short, gritty rock n' roll riff or a Scare Chord. Worse is that you don't whether when or if he will ambush anybody in his way. Also, one of Peach's screams when she is eletricuted sounds like a realistic interpretation (i.e. screaming bloody murder) of feeling that type of excruciating pain in contrast to some of the other screams. Think about how she and the others feel in a more realistic way after that.

Super Mario RPG: Legend of the Seven Stars

 * In Super Mario RPG, there's a room in the Sunken Ship with a Mario clone that seems pretty harmless, like any other NPC. Except that said Mario clone TURNS INTO A GREAPER out of nowhere, and you enter battle. Still scares the shit out of me just thinking about it.
 * See this video for further details (at about 10:00).
 * When you initially arrive at Seaside Town in Super Mario RPG, there is definitely something off about the place. The townspeople all look identical, and display disturbing behavior, like stopping mid-sentence to quietly converse with each other, and watching you sleep. It eventually turns out that a Smithy Gang member named Yaridovich took over and impersonated the entire town.
 * Don't forget Smithy, himself. Imagine a cyborg-bearded-giant-king-thing, with More Teeth Than the Osmond Family, and a couple of replacable heads, each just as creepy as the original.

Paper Mario Series
Has its own page.

Superstar Saga

 * When you battle Cackletta in the Hoonversity, she turns into an indescribable abomination before you battle - and spends the final chunk of the battle in that form. Meep.
 * This was the first Mario game to feature apparent actual death of NPCs, mainly Toads. Why?? The series is so lighthearted, why add death to it?
 * Is there a video showing the toad deaths, or of other NPCs?
 * Cackletta possesses Bowser and turns him into a mutant hybrid of the two. And to fight her, you have to go inside Bowser and fight Cackletta in the form of some spirit/gas thing and attack her heart.

Partners in Time

 * The Shroobs. They are basically evil mushrooms that invade the Mushroom Kingdom because their home planet is a barren wasteland. They reduce the Mushroom Kingdom to rubble, and take it over. Then, they begin taking the population and turning them into FUEL FOR THEIR UFOS!? WHAT THE HELL NINTENDO!?!
 * Actually, I met some kids who said they came up with the shroobs, and submitted their design. I know, it sounds sketchy, but this was before Partners In Time, so I believed them.
 * The theme of Shroob Castle.... God it's horrifying...
 * The Elder Princess Shroob: she is a giant, mutant with numerous tentacles for legs and for arms, and a hideous face, and attacks by even shooting down her own men... Also, her battle music is a strike in "Soundtrack Dissonance".
 * Oh dear god, Toadwood Forest and the Vim Factory, The Shroobs are using Toad BLOOD To power their spaceships. Also, after defeating the Swiggler you can still find Toads strapped to the trees!
 * When Peach first goes on her trip, she is accompanied by two Toad attendants. You get to watch one of them die. And the second one traumatically loses his memory for most of the game, which is at least softened by how he recovers, survives and returns as comic relief in the third game.
 * When Peach first goes on her trip, she is accompanied by two Toad attendants. You get to watch one of them die. And the second one traumatically loses his memory for most of the game, which is at least softened by how he recovers, survives and returns as comic relief in the third game.

Bowser's Inside Story

 * Mario and Luigi Bowsers Inside Story. Much of the game takes place inside Bowser's body. Which is strangely maze-like and platformer-esque. You have to manipulate Bowser's organs at times to get Bowser moving or affect him. This troper finds the idea of running around inside a giant living organism creepy as is, but the idea that Bowser has these characters running around inside him affecting his bodily functions and messing with his insides is a hell of a lot worse! Plus, some of the enemies are odd, virus-like versions of regular enemies such as Goombas. Enemies that Bowser inhales can damage him internally by attacking his body! And all the Toads are infected with a disease that makes them inflate in size and roll around uncontrollably! The whole thing is totally fucked up.
 * Even more fucked up: the final boss fight. It's really disturbing to think about.
 * The song played in Fawful's Castle from Bowser's Inside Story.
 * The in general is creepy - it is literally an embodiment of evil that can absorb other beings to use as a source of power as it does to Fawful! Not to mention he turns into an ! Oh yeah... IT SHRIEKS. 
 * The cutscene where the Dark Star chokes the Mario Bros. with its dark energy could be seen as this, but Luigi's Large Ham tendencies towards the end of the scene sort of make up for it.

Yoshi's Island

 * Yoshi's Island has many frightening elements, probably helped by the fact that it had excellent music and was able to create an effective atmosphere in a level with it.
 * If Yoshi is hit, Baby Mario is suddenly caught in a flying bubble, wailing desperately, as the player tries to get him back before the enemies catch him and fly away with him.
 * The threat of being eaten occurs quite a bit. Not only is there a boss battle that occurs in a frog's throat, but there are a few chase scenes in which a gigantic Chain Chomp is out to eat Yoshi.
 * Speaking of chase scenes, in the final level, there is an optional chase where Tap-Tap the Golden, a large spiked undefeatable enemy, is chasing Yoshi across a rocky, lava filled area, as the screen ever so slowly moves to allow him more area to move. It doesn't help that before entering this chase, if the player wants to receive helpful information, all they get is "RUN AWAY!!!" in dramatically huge font.
 * What arguably makes this even worse is that you're being chased by a boss that's nigh-invulnerable, and is large enough that you can hear the ground quaking from every step that it takes. Oh sure, your eggs manage to stun it, but that's about it. Not even it falling down a hole to its doom can stop it; it just springs forth like a proverbial bat out of Hell, and continues to chase you, its smile almost taunting you.
 * Kamek would enlarge small creatures in the boss battles. The transformations were complete with 'Time to Die!'-esque music.
 * In the final battle, where Baby Bowser, in an eerily designed toy room, attempts to ride (and therefore injure) Yoshi. After he has been defeated, Kamek turns him into Big Bowser. Big, meaning the castle he had occupied is completely destroyed by his transformation, and he could probably crush Yoshi with a single finger/claw. The transformation and battle is accompanied by rather horrifying music, if not the entire series,]] and the battle is pretty much Yoshi trying to hit him with large eggs to push him back, while he is slowly coming towards you. When he is hit, he is indeed pushed back, only to then run at full speed towards Yoshi, who is standing on a small ledge (which is being destroyed by the boulders that fly in the air from Bowser's roars). If Bowser comes close enough, his stomach obliterates the ledge, leaving Yoshi unable to do anything but plummet to his death. This can be extremely scary when one is desperately trying to get him further back, knowing that he will run at full speed afterwards.
 * What makes this even worse? When he has one hit left, he'll continue to run towards you, and will not stop until he collides with Baby Mario and Yoshi.
 * "Touch Fuzzy, Get Dizzy."
 * Your primary method of attack in this game is that you eat your enemies, and then transform their digested corpses into ammunition, which you then throw at their comrades, who no doubt just watched you consume their friends seconds earlier. If that's not just a little bit disturbing...
 * Consider that this ammo is eggs. Yoshis use their unborn young as ammo.
 * The sound of the Lunge Fish is one of the most terrifying sounds in video games.
 * The Lunge Fish itself. It just comes right out of nowhere and eats you, killing you instantly.
 * Those giant Chain Chomp heads that fall from the sky. Not only the fear of getting hit and falling into the holes they leave, but those faces.
 * Gargantuan Blargg and Nep-Enut can be pretty scary for kids too, with this giant red/blue thing popping out of the lava/water out of nowhere, especially if you don't realize there are eyes there.
 * Neglecting to retrieve Baby Mario in time rewards you with and image that consists of the Toadies carrying Baby Mario away against a black background. The noise they make doesn't help.
 * On that note, the "Game Over" screen deserves a mention here. It shows "GAME OVER" in a deranged font zooming in and rotating in random directions. The same animation repeats itself several times afterward until you either continue the game or shut it off. The depressing piano ditty that plays under it and the fact that SNES games with pre-rendered 3D graphics were in their relative infancy only make this worse.

Yoshi's Story

 * Inside the Magma Castle lurks an enemy not found anywhere else in the game--the Attacky Sack, a colorful, patchwork ball with OH MY GOD, RAZOR SHARP TEETH, IT'S FLYING RIGHT AT ME, OH MY GOD, OH MY GOD, MOMMY, MAKE IT STOP! t=2m30s Watch this, and be enlightened.
 * Oh yeah, and it's invincible.
 * Two words: "Blargg's Boiler." Everything in that lava-filled hellhole is a bit scary, whether it was the giant monsters with GAPING MOUTHS that jump out of the lava and ROAR AT YOU or the lava-ghost things... the noise they make... that SHRIEK...
 * And then when you lose a Yoshi, these cutesy-yet-horrible flying things carrying it through the air to the dark castle as tears fall from its face, oh, God...
 * The Cheep Cheeps in the jungle levels scare some.
 * The last page of the game has four different themed castles, each of which is terrifying in its own way. Mecha Castle has machines that can crush or flatten you. Lift Castle is filled with buzzsaws that try and kill you. Ghost Castle, probably the least creepy, is full of Boos and other ghosts. Magma Castle is filled with lava and some of the creepier enemies.
 * Mecha Castle, however, wins in Nightmare Fuel, as it features blades that pop out from walls and chase you, spikes, some saws, and the aforementioned one hit kill machines that move particularly realistically and violently. Magma Castle would be second, but it has a more epic and dungeon feel to it.
 * Big Blurp. It's another enemy that can eat you. And it comes in two flavors! The red one who jumps out of the water and the blue one who spits water to try and throw you in. Trying to get all the fruits possible in the previous section is a normal practice here.

2

 * The other Wario Land examples have nothing on the Really Final Stage of Wario Land II. It's like the inspiration for one of the rooms in Yume Nikki.

3

 * Let's start out by saying that in Wario Land 3, nothing can kill you. Being hit by enemy attacks causes some kind of inconvenience, such as knockback or a status effect (being set on fire, for example, causes Wario to run uncontrollably until he touches water or until the fire envelops him, giving you a short time to walk around, invincible and able to use the fire to solve certain puzzles, at least until it reduces him to a pile of cinders. Which he walks out of completely unharmed, being indestructible). After retrieving the Plot Coupons, you return to the temple holding the being that has advised you over the course of your quest to find out that, Seeing the Game Over screen after a whole game without it can render some kids unable to finish the game.
 * That ghost thing in The Vast Plains. It does not look harmful, but if you get close enough to it, it actually zooms down on top of you and makes the screen around Wario and the ghost all black, all the while closed-eye grinning. And the only way to reverse it is to bump into a wall or something similar.
 * How about the snakes in some of the levels. It's just that, after the snakes rise from their urns, their heads turn red, make the most cacophonic hissing this troper's ever heard in a video game and spew fire from their mouths. Thank god it's only temporary.

4

 * The Golden Diva from Wario Land 4 falls straight down, right to the bottom of the Uncanny Valley
 * And the fact that she when it attempts to oppose her.
 * In general, most of the audio and sound effects in Wario Land 4 are incredibly bizarre at times.
 * Many of the bosses in this game fall into Uncanny Valley, but Spoiled Rotten takes the cake. Once you get his health down to a certain point, he suddenly gets a disturbingly detailed face and huge, razor-sharp teeth.
 * The creepy imagery in the sound room.

World

 * The Wario World bosses. They're not creepy in the way the fourth game's bosses might be, but they fall so deeply into the Uncanny Valley that they just look totally wrong in all ways possible. The Mean Emcee looks bizarre, people have mentioned the Winter Windster as creepy on the series page and Clown-a-round... well, it looks so much like it's made of plastic that it seems unnerving. The fact it's face is located in the top of his next doesn't help matters either.
 * As for the Brawl Doll, kill it with fire. as seen here, it even laughs and turns its head 180 degrees when Wario approaches it.

Mario Party Series

 * The minigames in Mario Party 8 are, in all actuality, incredibly sadistic. Seriously, think about it. Half of the minigames only have one winner, meaning the others fall into ravines, get burned by Podoboos and fall into lava, get trapped inside computers, captured by Mr I... this game is not for those who care too deeply about what happens to the losers.
 * How about Specter Inspector? Once one player successfully finds three of the five creatures, the room lights up and the winner stands with all five as they all wave happily at the player. And then the camera zooms back to show that they're all trapped inside a painting in a dark room, as ghosts leer at it. Remember, this is the winner...
 * To say nothing of Bowser's Big Blast from Mario Party 2/4, and Cut From The Team from Mario Party 8. The tension alone makes the heart race in fear. Who will die first? Will it be you, or your friends? You're at the mercy of Lady Luck as you slowly step forward and meet destiny...
 * The entire Mario Party series is accidental nightmare fuel, especially the first ones. Any of the minigames involving Boos eating the losers was creepy.
 * When you think too much about it, hell yeah. There was Ghost Guess in the first MP where you had to guess which was the leader of a pack of Boos (a dozen or so) circling you. The game gives you the tip: the first one to start their dances is the leader. But then again, it's pretty hard to figure out which of them does it. And when you pick the wrong one... Shudder.
 * And then there's Pedal Power, one of the games that used the infamous Scrappy Mechanic of "spin your Control Stick around like there's no tomorrow". You have to pedal a stationary bike to light up a lamp behind you before the Boo gets you. And that minigame is so freaking hard, I have never seen the CPU players pull it off in all the times I played MP1. Never. With just a sliver left to light up the bulb (as if it wasn't lit enough), the Boo always catches up and drags the poor guy away. Nice job breaking our sanity, Hudson.
 * The tension-inducing music does little to help matters.
 * Speaking of the original, some find the Options House terrifying! Mainly because of the freaky background music, but also the process that you go through to delete your save data feels like you're activating a nuclear missile!

Luigi's Mansion Duology

 * The scariest part probably was when lightning struck the mansion and cut the power off. So every single previously safe haven was now a miniature hell hole of never ending ghosts and could only be stopped by finding a special ghost looking at himself in a mirror and you're never told which one. A little over half of the rooms of the mansion have mirrors!
 * The game itself is one thing, but the game over screen from the beta version is quite another, due to Luigi looking literally scared to death.
 * How about the other ending pic? It's a bit less creepy, but Luigi looks just as terrified see here
 * Trying to capture Luggs, the huge ghost in the dining room, was terrifying. The fact that this enormous ghost is spitting fireballs, then calmly going back to his meal once the candles are relit, is just disturbing.
 * There is a lighting oddity It's mostly the fact that it's an almost unnoticeable effect that appears for only a split second that makes it scary.
 * What about Bogmire? Seriously, the guy didn't even have any features that defined if he was alive or not, he looks more like a monster than a ghost, and don't get me started about the shadows...
 * The ? Seeing him banging his fists while King Boo laughing in the background was terrifying.
 * How Luigi was for the final boss fight, as it
 * Any scene with the Boos. King Boo gets special recognition, though.
 * What about the music? It may be extremely catchy but it's the icing of Luigi's Mansion.
 * Boolossus' theme. *shudder*
 * The first encounter with a ghost. You walk into a dark mansion on a stormy night, greeted by a pitch black room with only a few candles. You turn on your flashlight and walk up the stairs, and try the double doors. you find that they're locked and then suddenly a demented giggle comes from downstairs. You head down, and an orange floating orb holding a key appears and floats back and forth while bells sound in the background. Then it notices you, makes a little squeaky gasp noise, dropping the key, and floats up the stair and into the double doors, mysteriously putting out every candle just by the ghost being close to it, and then explodes into little orange clouds on contact with the door. A little finisher to the scene is a zoom in on the key on the ground, with a little jingle.
 * Dying in Luigi's Mansion is pretty creepy as well. Luigi falls to the floor while the screen goes black and white, and then the words "Good Night..." appear on bloody red letters. Which slowly go black and white themselves.
 * Probably better than the aforementioned beta Game Over screen, though.
 * What about the room with taxidermy animal heads? At first they're fine, like any you've seen in your life, but nothing happens in the room so you vacuum everything. But when you get to those heads, they start nodding! Just... nodding! It doesn't sound so bad but it looks disturbing.
 * Apparantly, In the Safari Room, there was originally supposed to be a Portrait Ghost in this room, but was removed in the final version because it was deemed too scary to be in the game. It was supposed to resemble an Australian hunter that would shoot the player.
 * After you capture the ghost Lydia, a cutscene happens where the camera zooms in on a door whilst a baby's crying can be heard along with a creepy music box tune...*shivers*.
 * It doesn't help that the baby is crying since you technically KILLED his mother and father, and then plan on murdering him.
 * The Observatory Room. Maybe it's the fact that it seems like you're actually in space, the fact that there is actually a fake moon in there, and that the outside music actually plays in the room, pretty much confirming that your in a space of sorts.
 * The pause menu too, it has a door with Luigi's shadow hanging on it, creepily.
 * The pause menu too, it has a door with Luigi's shadow hanging on it, creepily.

Super Princess Peach

 * Super Princess Peach. In Bowser's Villa, there are a couple of segments that contain several faceless Peach statues and a HUMONGOUS Thwomp that takes up the entire background. Before it opens its eyes to scan the area, you have to copy the poses the statues are in. If you fail to do so, you'll be sucked into his gaping mouth. Of course, you'll only be sent to the beginning of the segment, but still...
 * And then there's the wall of Langolier-like Boos.
 * Perry devours baddies to recover the Vibe Gauge. If there are no enemies nearby, one can stand still for a few seconds, cuing an idle animation where Perry latches onto Peach's head, to her vocal displeasure, regaining Vibe Gauge that way.

Super Mario Bros. The Movie

 * Koopa coming on to Daisy. With his face and tongue getting... less human. (Early drafts suggest he was attempting to rape her.)
 * The Goombas. Except Toad.
 * Lena at times; her head motions and hisses invoke the Uncanny Valley.
 * Koopa snapping and attacking Luigi after politely asking them for the rock.
 * With a bit of Fridge Logic, the brothers dissolving between dimensions. Mario was conscious of the fact that he disintegrated.
 * Koopa's Transformation Ray.
 * The Snifits, due to those weird noises they were constantly making.
 * The Jump Scare of the Tyrannosaurus lunging out.

Other

 * This "realistic" Mario image is Uncanny Valley personified.
 * Everything has eyes. You can't go anywhere without being watched.
 * Brawl In The Family noted this.
 * A fear of heights as well as death by falling makes playing Mario Galaxy and Mario 64 terrifying sometimes.
 * The Super Mario Bros. Super Show! episode "Count Koopula" featured pretty creepy looking and sounding Giant Spiders that wore Snifit masks.