And Then John Was a Zombie

No, All The Tropes. You are the demons.

And Then John Was a Zombie is essentially a literal version of He Who Fights Monsters. It is a situation in which a character, frequently a protagonist, is turned into the very thing he or she has been fighting; a survivor of a Zombie Apocalypse may get bitten by a zombie, a demon hunter may be possessed, and so on.

A popular variation of this is for protagonists to have this thrust on them as an Emergency Transformation, and/or use (or attempt to use) Heroic Willpower to avoid the Face Heel Turn frequently associated with this trope and use the powers for the cause of good. Results may vary. Of course, it is also possible for this to happen to villainous characters, particularly Non-human villains, though it is certainly possible for this to happen to human villains, especially in stories where The Virus has strong presence, but is not the sole villainous force. Depending on the villain and the type of transformation in question, results can and often will vary even more than heroic characters suffering this.

If poorly foreshadowed, this can very easily be a Shocking Swerve. Opposite of Tomato in the Mirror, in which case the main character was the monster all along. Also contrast Can't Stay Normal. Compare Doomed Protagonist, in which this was set up as an eventuality (or even a possibility) earlier in the story, The Virus, You Will Be Assimilated, and for variations in which the transformation doesn't force or suggest a Face Heel Turn on the victim's part, Viral Transformation.

Examples will contain spoilers!

Anime and Manga

 * In Gensoumaden Saiyuki, Hakkai slays a thousand demons and his thousandth turns him into a demon, pointy ears and all.
 * In Uzumaki, after the teacher smashes a bunch of human hybrid snail eggs in disgust, he returns a week later a snail man. With a bunch of snail eggs growing on his back.
 * In the end,.
 * In Digimon Savers, the main human villain, Kurata, has a great fear of all Digimon and kills a bunch of them in the name of one-sided peace, but then uses their life force to power an even worse villain-type Digimon and become one with it to ultimately take over the world.
 * In School Mermaid, the main character ends up being pulled down into the floor by the very mermaids she was hunting and becomes one herself. And it is strongly implied that her best friend will hunt her down and eat her later.
 * In Shiki,.
 * In Kakurenbo, the main character wins the game of hide-and-seek by being the last child to be found... and then is given the honor of being the new "it", that is, he becomes a demon himself.
 * One of the truly Awful Truths that Magical Girls have to face in Puella Magi Madoka Magica is that . This is especially illustrated in Episode 8 when this happens to.
 * In Shikabane Hime,.
 * In "Umineko no Naku Koro Ni" EP5, "End of the Golden Witch,
 * Kannazuki no Miko: And then Souma was a petrified Orochi. He saw it coming, though, and try to use the Orochi powers contaminating his body to make a Heroic Sacrifice. He recovers later.
 * The Claymores who become Awakened Beings definitely qualify. Particularly galling in the case of Ophelia, as she really hates Awakened Beings, and became a Claymore to fight them.

Comic Books

 * The ending of 30 Days of Night involves the hero, Eben Oleson, turning himself into a vampire to save his friends. This counts because the vampires invaded to feed, not to create new vampires and the humans (until that point) weren't interested in becoming vampires.
 * In the fictional comic book Tales of the Black Freighter, a story within a story from Watchmen, the protagonist

Eastern Animation

 * At the end of the short His Wife Is a Hen, the husband becomes a chicken.

Fan Works

 * This trope is named for the legendary Cruel Twist Ending of the fanfic Doom: Repercussions of Evil, wherein John Stalvern, who has spent the story fighting demons, becomes a zombie himself. (Or possibly was a zombie from the beginning, fooled by Satanic illusions into seeing humans as demons. It's not totally clear.)
 * Now with dramatic reading -- brought to you by YTMND.
 * This beautiful piece is a rewritten version that both triples (or something) the length of the original story AND gives it a better feel overall. Still not as good as the original, though.
 * And then there's this version (at 6:49)
 * Arby 'n' the Chief: And then, JOHN WAS THE ALIENS!
 * In the How to Train Your Dragon fic Cursed, Hiccup.
 * In the Fullmetal Alchemist fangame Bluebird's Illusion, Ed becomes a homunculus in one of the endings.

Film

 * Halloween 4: The Return of Michael Myers had this at the end with the little girl holding Michael's butcher knife, implying that she has become the new killer.
 * The Producer's Cut of Halloween: The Curse of Michael Myers ended with Dr. Loomis being marked with the Curse of Thorn to imply that he would carry on Michael's taint. This was one of many things dropped in the theatrical version, although this one happened because Donald Pleasence died.
 * At the end of the 30 Days of Night movie, the protagonist has to become a vampire in order to fight off the vampires that have been eating everyone.
 * In the Doom movie, Reaper is dying and his sister subjects him to the chromosome which had turned everyone else into monsters. Luckily (and perhaps subverting this trope) he is among the small percent of humans who don't turn into monsters when exposed to it and instead become 'angels'.
 * Arguably played straight by the "protagonist" Sarge turning into a demon.
 * In the end of Roman Polanski's 1967 film The Fearless Vampire Killers (and the subsequent 1997 musical adaptation, Tanz der Vampire),
 * The 1970 film Count Yorga Vampire has this three-fold,
 * A reversal of the kind of ending mentioned above occurs in the 1971 sequel, The Return of Count Yorga,
 * A homage to the endings described above occurs in the 1996 Tales from the Crypt movie, Bordello of Blood.
 * A similar ending occurs in the 1983 film Halloween III: Season of the Witch.
 * Ken Russell's 1988 film The Lair of the White Worm also concludes in a similar fashion.
 * Occurs in Dragonball Evolution when Goku turns into the Oozaru, said to be an unstoppable servant of Piccolo, after having spent the movie determined to defeat Oozaru. Only after does he get out of it. This is not the case in the original source material, where the Oozaru is not mentioned until Goku transforms for the first time.
 * In Pumpkinhead, a man summons a spirit of vengeance (the titular Pumpkinhead) after his son is accidentally killed by reckless teenagers. Realizing how screwed up things have become, he tries to stop Pumpkinhead, to do so, he himself must die. At the end of the film the man has to become the next Pumpkinhead.
 * In Van Helsing, the Live Action movie, Van Helsing becomes a werewolf to battle Dracula because apparently vampires are weak against werewolves.
 * David Cronenberg's Shivers...and then Dr. Saint-Luke was Infected. Ironically, David Cronenberg considers this a happy ending, as he's said the Infected are happy and free of their inhibitions, and at the end they're about to.
 * The uber-creepy 1978 film of Invasion of the Body Snatchers ends with Veronica Cartwright's character approaching Donald Sutherland's character (he was the protagonist). As she calls out to him, he wheels around, points at her, and emits an inhuman wail (sort of the Pod People's call to arms).
 * At the ending of The Thing, it appears as though the Thing was killed in an explosion. However, Mac and Childs are still around, and it's not revealed whether or not they had been infected, leaving them to wait and see what happens.
 * All the alternative endings of The Ruins show the Final Girl succumbing to the evil in some way, while it is suggested in the theatrical one.
 * At the end of The Chronicles of Riddick, Riddick, which was foreshadowed very strongly early on,
 * In Timecrimes, Hector gets stabbed in the arm and chased through the forest by a man in a black coat with his head covered by bandages. Then he travels backwards in time an hour, cuts his head, and begins bandaging the cut. Realizing that he's in a Stable Time Loop, Hector completely wraps his head in bandages, then takes a pair of scissors and attacks his past self, deliberately causing the series of events that led to his climbing into the time machine an hour ago.
 * In the 1990 remake to Night of the Living Dead Ben is badly wounded by Cooper during the night and as a last resort locks himself in the basement against the zombie horde. When we last see him, the door seems to be holding, but Ben has no supplies and his wound is worsening. When Patricia returns the next day with a group of locals, they eventually manage to open the door to the basement, and encounter the now zombified Ben.
 * At the end of Candyman the heroine becomes a Candywoman.
 * At the end of Vampire Assassin, the protagonist becomes a vampire.
 * Near the end of Undead or Alive Elmer makes the mistake of punching an infectious zombie in the mouth, and almost immediately realizes that he is beginning to turn. While he uses the last few moments before the hunger overwhelms him to attempt to make a Heroic Sacrifice, he succumbs in the end, infecting one companion and convincing him to help devour another.
 * Skyline has.
 * Star Wars prequels: and then, the Jedi Anakin Skywalker became the evil Sith Lord, Darth Vader.
 * becomes part-demon after surviving Jennifer's attack in Jennifer's Body.
 * In the final scene of the movie Deadgirl we find out that the main character has become a despite spending the entire movie trying to dissuade his friends from doing the exact same thing.

Literature

 * In John Dies at the End, it is revealed in the penultimate chapters of the book that somewhere along the course of the story,, becoming the very doppelganger that part of the story's arc has revolved around. Considering the character John  , this could be a subversion. Especially likely considering the writer is Cracked Editor David Wong.
 * In Necroscope, vampirisation happens to the good guys every now and again. Eventually,.
 * In Hater by David Moody, the main character
 * In the Newsflesh book Feed,
 * In P C Hodgell's Kencyr series, a singer named Ashe is bitten by haunts (ghouls with an infectious bite) during a battle early in the second book but hides her wounds. By the time of the final battle in the book, she is technically dead (but hiding it well and fully in control of herself), and plays a key part in the main protagonist's (Jaime's) survival: Ashe guards Jaime's back while taking wounds that would have killed a living Kencyr many times over. Ashe's motives are unclear but seemed to include dispassionate curiosity.
 * Waves Put Out The Wind by the brothers Strugazkiys has a commission that ensures that no Sufficiently Advanced Aliens can improve human history unnoticed. One of employees gets some hidden superpowers activated while investigating a superhuman organization.
 * Shinigami God of Death by Django Wexler has the younger of two sisters
 * Animal Farm ends with
 * Abraham Lincoln: Vampire Hunter has the twist ending of...well, guess.
 * Goosebumps:
 * In The Werewolf of Fever Swamp,
 * Calling All Creeps. Some reptilian monsters that can turn into human form come to think that the protagonist, a boy bullied by most of his school, is one of them. They have plotted how to transform everyone in school, and then on town, country and world, in Creeps like them and the hero is trying to stop them from feeding everyone the transforming goo.

Live Action TV

 * The end of Supernatural season three seems to apply to Dean.
 * By the end of season four,  you are the demons.
 * Used again with
 * Dollhouse Season 2.
 * How much does Joe of The Lost Room love his daughter? Well, after spending all the series trying to find the Object to rescue her from a Negative Space Wedgie, he
 * In the 1986 Twilight Zone episode "Monsters!", the presence of a (kind-natured) vampire in their neighborhood causes every normal person in suburbia to temporarily mutate into a pack of gruesome monsters that kill the vampire - afterwards, they're horrified at the murder, never realizing that they were the monsters.
 * In Kamen Rider Decade, this happens to In fact, this trope is a common theme throughout the Kamen Rider franchise, although the difference is that they were the "zombies" in the first place or take the source of their power from the very monsters they fight.
 * For a straight example, the earlier titular Kamen Rider Blade,  In order to prevent the impending apocalypse a single remaining Joker Undead would cause,
 * The Doctor Who episode "Survival" has this as the major plotpoint.
 * Are You Afraid of the Dark?: In "The Tale of the Chameleons", Janice gets turned into a chameleon and drowned in a well, and her Evil Twin plans to do the same to her friend and the rest of her family.
 * The Vampire Daries does this multiple times. First with Caroline's  and later with

Mythology

 * According to Japanese mythology, killing many Youkai (a thousand, according to some versions) results in their slayer being transformed into a youkai himself. Then again, anyone capable of killing 1000 demons is powerful enough to be considered a demon himself by most people, so this could just be a Lampshade Hanging on that fact.

Music

 * Black Sabbath's "Iron Man." Through a Stable Time Loop, a man travels to the future and witnesses The End of the World as We Know It at the hands of the titular villain, then travels back in time to warn people about the coming threat, but in the process is transformed into Iron Man himself.

Tabletop Games

 * The end result in Changeling: The Lost for changelings whose Clarity gets too low and their Wyrd too high. They leave for Arcadia and become exactly the same as the monster who kidnapped and abused them in the first place.
 * White Wolf in general is in love with this trope, as it is likely to come into play in both versions of Vampire and Hunter, old Wraith, Kindred of the East, and Demon: The Fallen. It is also possible in both Mages, Werewolf: The Apocalypse, Changeling: The Dreaming, and Orpheus. The list just goes on....
 * Warhammer Fantasy Battle and Warhammer 40,000 use this trope heavily. In 40k, it is Turned Up to Eleven, where not only do you turn into a horribly misshapen mutant/Chaos Spawn/daemon, but you also have a good chance of winding up causing the deaths of billions.
 * Warhammer 40,000 Roleplay series feature extensive rules on corruption by the Ruinious Powers to reflect the setting's spirit.
 * This is a quite common fate for any investigator in Call of Cthulhu, ranking perhaps just below "killed by horrible monster existing in fourteen dimensions at once," "lab rat or soul-in-a-jar for horrible monster," "spends remainder of his or her life eating cockroaches in a padded cell," and "gets brain stolen by horrible monster."
 * Subverted in The Whispering Vault: People who investigate the Unbidden and survive tend to be turned into Stalkers...but given how a Stalker's entire purpose is to protect reality from Unbidden and retain most of their human personality, this comes off more as a transhumanist reward.
 * In Birthright killing one of the Blooded, especially those who didn't proclaim a heir, spills their power to be "inherited" by anyone in the vicinity, and specifically to the killer if killed with a special weapon or by stabbing through the heart. A bloodline acquired in any way may dominate equal or weaker one, and bloodline of Azrai that tend to twist people into Awnsheghlien ("blood abominations") is more "sticky" than the rest. An Awnsheghlien usually collects reputation as a serious threat pretty quickly, but - three guesses as to why they are so hard to eradicate.
 * Some Yu-Gi-Oh! cards have images that tell stories. One is the Gagagigo series; it starts as the Gigobyte, who wants to fight monsters... and ends with Gogiga Gagagigo, whose soul has ceased to exist and his body only moves on a drive for power. Then there's Warrior Dai Grepher; the first card of his story shows him and other warriors and spellcasters fighting demonic creatures. Then the series goes on and he becomes Dark Lucius. In Sakuretsu Armor, Dark Lucius LV6 can be seen striking down some of the people he fought alongside in that first card.
 * Gigobyte starts down the road to evil soulessness by modifying himself to get more power to defeat the Invader of Darkness. Since the story is spread over the flavor texts of many cards over a few different expansions, it doesn't come as too much of a surprise. The compiled story is here if you're interested.
 * Magic: The Gathering gives us Karn, a golem created to fight the Phyrexians. But his heart was a Phyrexian stone, normally used for insta-You Have Failed Me.... This stone contained, like all artifacts of Phyrexian origin, the oil, which took hold on Mirrodin. Karn almost gave in to the Praetors' whispers.
 * The Innistrad Block has a fetish for these, and with good reason, as the story line has nearly all monstrosities coming from mankind. In particular, "church warrior becomes zombie" seems to be very popular.

Theater

 * Alfred, the assistant vampire hunter in Tanz der Vampire, becomes an undead bloodsucker himself at the end of the show. Worse, the vampire that turns him is none other than Sarah, the girl he loves and was trying to save. However, in the Musical this isn't depicted as especially bad, as due to sympathy-songs etc. the spectators are expected to have sympathy with the vampires and the only one really wanting to kill vampires was the professor.

Video Games

 * Blizzard seems to love the trope.
 * At the end of Diablo, the hero defeats the titular boss and jams its soulstone in his/her own forehead to contain it. This results in This was later retconned in Diablo 2 by saying that said hero was more or less mindraped into doing so.
 * It's uncertain how long Tal Rasha held out containing Baal this way, but considering the Diablo 2 expansion, it's probably safe to say that anyone who fights demons succumbs to this in some degree.
 * And again in Diablo 3. Leah, niece of Deckard Cain starts off as a genuinely Lawful Good character. Then she finds out that
 * In StarCraft, Kerrigan fights the Zerg during the Terran campaign but becomes one during the Zerg campaign.
 * Similarly, Arthas and Illidan in Warcraft III. Note that in the cases of Kerrigan and Arthas, the trope is in that they become leaders of the factions that they opposed, not those that they first joined.
 * Sylvannas fights Arthas' undead right up to the point where she was killed and resurrected as a banshee.
 * A playable example: No, warlock. You are the demons.
 * This happens in Knights of the Old Republic, after The Reveal; always for Bastila and optionally for the player.
 * In the Possessed ending of Silent Hill 3
 * Silent Hill 3 uses this trope earlier, when Vincent  This being Silent Hill, whether or not he is telling the truth is deliberately left vague.
 * In the worst ending of Silent Hill Homecoming, Alex becomes a Pyramid Head.
 * In Silent Hill: Downpour,
 * Disgaea 2: Cursed Memories's worst ending features this. In spades. To elaborate, if Adell has met the required conditions, Cue crunching sounds.
 * The good ending of Eversion turns your character into The bad ending has
 * Unless, of course,
 * In La Pucelle, if you defeat certain powerful enemies in the Dark World/Netherworld (which requires a lot of Level Grinding), a band of demons will appear and declare Prier their new ruler... which Prier rejects out of annoyance after being teased by her teammates, and the game continues anyway, ignoring this interruption. However, if she continues on past that, becoming even stronger, she triggers a Nonstandard Game Over as the demons make her their new ruler for good and her friends abandon her. Prier being a demon queen is the Canon ending, as she puts in several appearances in the Disgaea series as "Demon Overlord Prier," a powerful optional character, as a half-demon with wings and a horn.
 * Curiously, the plot still ignores this. Until the Updated Rerelease for the PSP, that is.
 * Possible example: In Quake IV, at a particular point that marks roughly the midpoint of the game, the protagonist is converted into a Strogg in all but allegiance. Were it not for a very well timed raid by the good guys, our hero would have crossed the point of no return, as he was almost the entire way through the conversion process by that point. He then became a Phlebotinum Rebel. Wanna see?
 * The Bydo love pulling this on humanity's heroes in the R-Type series.
 * It first happens in R-Type Delta, if the player is piloting the R-13 Cerebrus—that particular fighter proves incapable of escaping the final level, and the Bydo exact revenge by converting the ship and its pilot into a tree-like Bydo.
 * Then there's R-Type FINAL, in which one of the Multiple Endings leads to the player getting converted into a hybrid Bydo/human/R9-Series...thing...and is sent back to the first level of the game, fighting both the Bydo as well as its former comrades. (It's worth noting that at the start of the game, you can see your future Bydo self fly by at the very start of the level!)
 * R-Type Command also pulls this on an entire human fleet at the end of the Human campaign—in fact, the player's character in the subsequent Bydo campaign is the former human commander. In both the case of FINAL and Command, the player's characters have no idea that they're no longer human and can't understand why Earth's forces are out to get them.
 * In the end of Super Paper Mario, Luigi ends up as part of Dimentio's plan and pilots a giant robot before being cured by Mario. It was implied something might happen to Luigi a few minutes before that, though.
 * In Castlevania 64's Downer Ending, you get this on two levels; a side character, Vincent the vampire killer, becomes a vampire. Also, Carrie agrees to marry Malus (Dracula), to which he ominously notes that they have "a binding contract".
 * Castlevania: Lords of Shadow:
 * If you unlock the true ending path of Aria of Sorrow, then upon defeating, who has declared himself Dracula's reincarnation, is revealed to actually be the reincarnation of Dracula. And if you get the bad ending, by losing to the True Final Boss, then he quite literally becomes the "second coming" of Dracula, in mind as well as ability.
 * In Gemcraft Chapter 0, the force you're trying to claim takes over, but it's a prequel and the truth was fairly obvious based on the events of the first game.
 * The ending of Fable: The Lost Chapters gives you the option of putting on Jack's mask, becoming his new host.
 * Both Baten Kaitos games use this, albeit in very different ways.
 * In the end of Resistance 2,
 * Happens in Prince of Persia: Warrior Within, when the Prince puts on the mask and finds himself transformed into the Sand Wraith. This makes him not only a monster but a doomed monster, as he saw the Dahaka kill the Sand Wraith in the past. Fortunately, he is ultimately able to Screw Destiny and return to his normal self.
 * And played straight in Prince of Persia: Two Thrones, where the prince is partially turned into a sand monster, complete with Heroic Willpower and a light sprinkling with a Gollum Made Me Do It-voice, though that seems to be there more to be defied than blamed.
 * Umineko no Naku Koro ni. EP5.
 * The worse endings of BioShock (series) have you becoming just as much of a monster as Andrew Ryan
 * Also done to a degree earlier. In order to complete the game it's necessary to.
 * Shadow of the Colossus has Wander gradually becoming less human, and ends with Wander becoming a new version of Dormin's body himself. It fails, and he reverts to human form, but as a newborn with demon characteristics. It's heavily implied that he becomes the ancestor of the horned boys in Ico this way.
 * At the end of the second act of Marathon: RED (a Game Mod), the hero is mutated by The Virus, and his former allies turn against him for a stage, but he turns Phlebotinum Rebel.
 * In 6 Days a Sacrifice, the main character, Theo DaCabe,
 * The ending of the incredibly obscure computer game THE SCREAMER. (Yes, it really is in all caps like that.)
 * The ending of the original Condemned seems to imply that main character Ethan Thomas has become one of the demonic freaks causing all the chaos in the game. The sequel josses this, as Ethans winds up as a burned out alcoholic bum,
 * At the end of Apocalypse, Bruce Willis's character is demonically possessed.
 * In the end of Alone in the Dark 2008, either Carnby or Sarah becomes a demon of Lucifer.
 * In Kingdom Hearts, Sora
 * Birth by Sleep:
 * Halfway through the First-Person Shooter Area51, your character gets mutated; this is also a case of Phlebotinum Rebel.
 * The other Area51 (the Light Gun Game) has this on the Game Over screen, which also happens to be the Game Clear screen.
 * Happens at the end of God of War, as amusingly portrayed in this comic strip.
 * In the final installment of Xenosaga, one of the many antagonists, Dmitri Yuriev, tries to conquer his fear of God by becoming a god himself . It works, of course
 * In Streets of Rage, the player is one of three ex-police officers finding themselves duty-bound to stop the assorted crimes of Mr. X, a powerful crime kingpin. In the final level, Mr. X offers to make you and your co-op partner into his right-hand men. If one player accepts and one refuses, Mr. X sits back and watches while you and your former partner solve the disagreement the only way they can. If the "heroic" player loses the fight, the remaining player goes on to fight Mr. X, and if successful...No, Axel, You Are The Crime Lord.
 * Possible again in the fan remake for any character, including
 * Beyond Dark Castle: And then Prince Duncan was the Black Knight.
 * Dead Space Extraction:
 * In Legacy of Kain: Soul Reaver 2, it turns out that And that he is doomed to fulfill this fate over and over again  In true mind-breaking Legacy of Kain style, this is also Tomato in the Mirror. There's a Tomato in the Mirror because John became a zombie at the end.
 * At the end of Red Dead Redemption's Undead Nightmare story, the main character returns from the dead as one of those zombies he has spend the whole game fighting (thankfully, due to some special circumstances, he turns out to be a sentient one). And the character's name? John Marston. The Achievement for completing the game directly quotes the Trope Namer.
 * Happens in the end of Throne of Darkness, to the Magnificent Seven Samurai. After defeating the Dark Warlord, their feudal lord reveals that.
 * In the Nonstandard Game Over of Metroid Prime 3, Samus is "terminally corrupted" and turns into Dark Samus.
 * In Oersted's chapter of Live a Live, he spends most of the chapter trying to vanquish the Demon King. Then, he decides to become the Demon King, thus setting the stage for the rest of the game.
 * This is the bad ending of The Breach.
 * In Portal 2, you spend the first half of the game with a robotic sphere named Wheatley trying to defeat GLaDOS.
 * In the escape-the-room game Poco Escape,
 * In the bad ending of the first Kid Icarus game, Pit is turned into a monster. Oddly, it's Palutena that does it to him. Maybe this is really supposed to be the joke ending?
 * The backstory of Byakuren Hijiri in Touhou 12 is this played sympathetically; originally a youkai-hunting priestess, Byakuren came to appreciate her youkai allies more than her human ones, and that combined with the fear of death drove her to transform herself into a youkai. Sanae recieves a warning that she who hunts youkai may become one, as well. In her profile, it's mentioned that Alice was a human who became a youkai to pursue power. In supplementary materials, Marisa is confirmed to experiment with methods of gaining immortality, but in one game she refuses to eat an immortal person's liver to get it. Reimu also has that option, and doesn't balk at the method so much as the idea of becoming anything remotely inhuman.
 * In The World Ends With You, after several days of battling Noise, undergoes an Emergency Transformation and eventually manifests as one. Subverted slightly in that the transformation only serves to introduce her as a Living MacGuffin, rather than invoking any Internal Conflict Tropes on her part.
 * In Dungeons of Dredmor, the first 3 levels of Demonologist give you resistance to Righteous damage, and useful powers when fighting demons. Any further than that, and you lose all that resistance in exchange for more versatile moves. What's the name of the penultimate level, giving you a chance to transform in to a literal combat monster? 'No, you are the demons'.
 * Happens in Metal Slug 2/X and 3, with MS2/X setting the players against mummies, and MS3 being the literal trope.
 * Happens in one of Kichikuou Rance's endings, where Rance, depressed either for Sill's death or absence (if the player is taking too long in rescuing her) finally gives in to Satera's suggestions of becoming the Demon King, committing immediately after a Moral Event Horizon Then he becomes a powerful Demon King, who crushes without trouble the human nations, with Satera at his side.
 * Played for laughs in the Hidden Object Game Sinister City. In the end,
 * Played for laughs in the Hidden Object Game Sinister City. In the end,

Web Original
"Washington:"
 * A skit from Those Aren't Muskets featured on Cracked.com, "Dealing with the Guy who's Clearly Hiding a Zombie Bite" ended as more and more members of the group revealed that they'd also been bitten by zombies, until the couple who hadn't been agreed to be bitten so as not to be left out. Of course as it turned out the original guy had also been bitten by a vampire and a werewolf. In the end, we had a group of three zombies, a werezompyre and a mummy werezompyre that also happens to be a criminally insane android with holographic legs and a webshow. Michael Swaim can officially give Cyborg Pirate Ninja Jesus a run for his money.
 * The Red vs. Blue: The Recollection trilogy drops several hints that the Meta, a shell of a man now playing host to a group of rogue A Is, was once a Recovery Agent dispatched to collect stray AIs from the field. This made explicit when he is seen in "Past" time in season 9.


 * Attempted by Chief in Arby 'n' the Chief, when his Machinima character, also named Jon, becomes an alien after fighting in a war against them. The effect was not as he intended.
 * Herobrine ends with
 * The first episode of Tobuscus Animated Adventures ends with Toby, who was bitten earlier by a zombie, turning into one and attacking his friend Gabe, interrupting the "Everybody Laughs" Ending.

Western Animation

 * Family Guy's parody of Lost - "We are the island!"
 * Finn and Jake of Adventure Time are both turned by the end of "Trouble in Lumpy Space". They got better.
 * Also in the Adventure Time episode "Mortal Folly/Mortal Recoil" Princess Bubblegum sends Finn and Jake to fight the Lich. In the end Bubblegum is turned into the Lich's vessel.
 * Parodied in Invader Zim in the episode "Balonius Maximus" in which the title character and Dib transform into bologna. The DVD Commentary hangs a lampshade on this.