This specific trope tends to fall into camp territory, because usually this revelation is made without any kind of foreshadowing or even any particular relevance to the plot- you can remove the plot twist and the rest of the story will still make sense. Like Kick the Dog, the main purpose here is to remove any doubt about whether the bad guys were really evil and killable.
This phrase actually shows up in comics a fair amount used by villains against heroes who are not technically human. Of course, from the reader's perspective they always fall on our side of What Measure Is a Non-Human?, so it just makes it seem like sadism for being willing to torture a sapient being. If your hero is the one shocked by their own non-human status, they might have just seen the Tomato in the Mirror.
In video games, this overlaps with One-Winged Angel, but only if the boss yells "Behold my true form!" beforehand.
When someone denies the humanity of genuinely human enemies in order to justify violence or mistreatment against them, it's dehumanization instead.
It should go without saying, but this page is loaded with spoilers. But as mentioned above, none of these plot points are particularly relevant overall, so don't fret too much about it.
Compare Just a Machine, which deals with this trope specifically for robots. Contrast The Man Behind the Monsters, where everyone but the leader is a non-human, and Human All Along, when what initially being thought as a monster turns out to be a human.
- Martian Successor Nadesico pulls an inversion reveal when it turns out the Jovians are really rebellious colonists with a lot of Imported Alien Phlebotinum. This just turns Akito from "scared" to "pissed off". In this case, it actually is an important plot point.
- In Hellsing, it turns out that the Major is a full-conversion cyborg. Subverted in that he still claims humanity because he has a human brain, and that his enemies would be perfectly willing to kill him if he were human anyway due to him being a Nazi nutjob leading an army of artificial vampires against London itself.
- Inverted in Vandread. The idea of harvesting body parts from humans is so repulsive to the main characters that they assume their foes cannot be human. They are human, and from Earth to boot.
- The final episode of Burst Angel. Turns out that an Ancient Conspiracy is behind everything. Yeah, that's quite an Ass Pull.
- In Naruto, when Naruto powers his way into the 4th Ninja War, he's told that the enemy army consists of plant-monsters and undead ninja. His response is basically, "Good! Now I don't have to hold back!" In this case, it's more a matter of "The enemy won't die so I can beat on them with impunity."
- In the second movie of Arpeggio of Blue Steel Cadenza DC, one of The Reveals is that the "Shouzou Chihaya" with Musashi is not actually the real Shouzou, who had been killed a long time ago, but merely a nanomaterial-made puppet with no will of its own.
- This may be the case with One Piece's Kaido of the Beasts. As one of the Four Emperors, he's definitely a contender for World's Strongest Man... but no one ever refers to him as a 'man'. He's called the strongest "creature" in existence (Whitebeard was the "strongest man"), and Charlotte Linlin (herself an Emperor) refers to him as "that thing". He has also shown the ability to turn into a gigantic eastern dragon.
- One of the old Johnny Turbo comics ends with this revelation against the strawman "Feka" corporation. Actually somewhat necessary to inflame the reader and justify Johnny Turbo's excessive violence, since the only crime Feka commits during the comics is doling out inaccurate information about video game systems. And making little kids cry by doing so. Amusingly, the Robotic Reveal only comes about because of said excessive violence, making it utterly ineffective as a justification.
- Shortly after Doom 2099 has taken over the US, he learns that Avatarr, CEO of Alchemax and one of the main Big Bads of the 2099 universe, is in fact an alien trying to rule the world via Mega Corps. Of course, Doom only learned this after he shot the guy's eye out.
- Doctor Doom in countless appearances anywhere in the Marvel Universe will turn out to be a Doombot.
- In Runaways, it was a Doombot working for Ultron.
- The film 300 uses this in one of the scenes where the Spartans are fighting the Immortals. A Spartan rips off an Immortal's mask to reveal that... They're Not Even Human! There's no suggestion anywhere else in either the plot or actual history that the Immortals were anything but, you know, just humans, albeit ones working for the supposedly evil Persian Empire. Or it's blatant propaganda by an Unreliable Narrator.
- They Live reveals the capitalists in Reagan era America are really Skullfaced aliens using a satellite signal to hide their true appearance.
- Inversion: The 13th Warrior. The fact that the I'm a Humanitarian monstrous attackers are human prompts the hero (and by extension, the audience) to be more horrified than when we thought they were monsters. After all, people have a choice.
- Stargate. While Ra was a long-lived alien in a human body, his Mooks were humans, and it never stops anyone, in the movie or shows. (Not that it isn't justified in these cases: they shoot back when shot at. It's just that Ra didn't become more killable by proving non-human: Thou Shalt Not Kill was never in effect.)
- Who Framed Roger Rabbit: "Holy smoke, he's a toon!" Normal toons aren't evil, but the reveal that the villain is one as well makes him both inhuman and much scarier in hindsight. He has been gleefully Dipping his own kind, and actually invented the chemical mixture that rendered his essentially-indestructible fellows vulnerable. Meaning this makes him even more of a monster than had he been human.
- Also crosses with One-Winged Angel because up until the steamroller an ending in which the police show up and arrest him was reasonable. It's already clear he doesn't have the psychological vulnerabilities which allow a toon to be restrained, and the revelation (complete with turning his body parts into power tools) pretty much puts him beyond imprisonment or subdual entirely.
- The sadly bungled movie Ultraviolet: in the final fight, Daxus turns out to be a "vampire" like Violet herself. Except that in the book, he just had night-vision goggles.
- The Lost in Space movie - actually, it's a case of the villain becoming a monster, but it has the same basic results, very baldly stated.
- The Lawnmower Man brings up the trope by name near the end (though not as a surprise, just underlining how far he's gone).
- At the end of The President's Analyst the good guys storm The Phone Company headquarters to rescue Dr. Schaefer. When the backup power comes on, they realize the TPC president is sitting nearby as he starts to politely admonish them for breaking in. After a few uncertain moments they realize, to their amusement, that he's an automaton.
Don: He's a recording!Kropotkin: It's like a visit with Abe Lincoln at Disneyland!
- Magic: The Gathering novels:
- In the climax of The Brothers' War, it's revealed that Urza's brother Mishra has been cyborgified, showing Urza that there's no hope left for peace or even victory. Foreshadowed earlier, plus there's the fact that the Big Bad himself is an even-more-advanced cyborg. Cue most awesome scene of mass destruction ever.
- Similarly, in the prequel novel The Thran, Yawgmoth's troops in the final battles are bizarre Magitek cyborgs, including some former colleagues of the main characters.
- Later, in Planeswalker, Urza is trying to eliminate Sleepers, Phyrexian artificial humans secretly infiltrating the population of his home world of Dominaria. Heck, Planeswalker proved that Yawgmoth was most definitely asleep at the helm, er, hub, of Phyrexia when the first batch of Newts were made. The kicker — somehow, despite having once been fully physical and human himself, a few millenia ago, Gix managed to forget that humans have different genders and reproductive, as well as waste, systems. The entire first batch of Newts (the Sleepers) looked human, but mostly teenaged boyish, with no genitals whatsoever — and glistening oil for blood. Way to go there, Gix, you schlep. This was improved on in later batches, of course, but this mistake proved costly for Gix...
- It is emphasized in Harry Potter that Voldemort, while born a human, has made himself less than human in some ways. Namely, by splitting his soul into multiple pieces, and to a lesser extent, by drinking unicorn blood.
- Inverted in an early H. P. Lovecraft story, "The Beast in the Cave", in which a man lost in a pitch-black cave hears something large and mysterious shuffling nearby and kills it with a rock. When his guide returns with a lantern to find him, they realize that the dying creature is a human being who'd been wandering in the cave for years, degenerating into an ape-like state.
- The White Witch from The Chronicles of Narnia is actually half Jinn and half Giant.
- Happens with individuals often enough on Buffy the Vampire Slayer that people eventually stop being surprised by it. It plays an important part in the episode "Ted", specifically.
- Monster of the Week Science Fiction shows have a tradition of inverting the trope. The main cast will assume they're facing yet another supernatural creature, and are shocked when they discover it was normal humans all along.
Dean: Demons I get. People are just crazy.
- The Torchwood episode "Countrycide" features a Cannibal Clan living in a small town as villains, with no aliens or alien tech present in the story. The audience surrogate, Police Constable Gwen Cooper, was much better at handling the revelation of the existence of aliens than that humans could be so terrible.
- The Supernatural episode "The Benders," when it turns out that a family of hillbillies has been abducting and killing people. Dean said it best:
- The homicidal inbreds from The X-Files episode "Home" weren't supernatural or robots or anything else non-fictional; they just had a whole lot of genetic defects that exist in real life.
- Smallville tries to resolve Thou Shalt Not Kill with Clark destroying Brainiac by invoking this trope. It's just a machine after all, despite all the characterization and its struggle to survive, right? Nicely accounts for Superman's irrational commitment to the idea that machines are never people, though.
- Averted with Doomsday. Everybody else is trying to convince Clark that his true form is a mindless killing machine, but Clark refuses to give up on the fact that there's a perfectly ordinary human/kryptonian/something that would be killed in the process.
- Played straight AND inverted in an episode of the most recent Twilight Zone series. A team of commandos is hunting a monster in the forest; said monster is very cunning and manages to kill all but one of the commandos, who is captured and taken to its lair. Turns out the monster is really a disheveled human. The reason why he's hunting people? The commandos, the people in the city, everyone is really an android; they overthrew humans long ago and copied their society.
- It appears rather often on Charmed, and in one case the whole episode ("Mr. and Mrs. Witch") plays itself out without the Charmed Sisters ever becoming aware of it. The Monster of the Week is in fact a demon, but he appears to be a human Corrupt Corporate Executive. The demon is quite aware that the Charmed Ones won't kill him as long as they think he's human, and in fact the Charmed Ones never do find out. The demon is still vanquished by his superiors for failing to accomplish their evil plan; and in fact, the Charmed Sisters read about this evil executive's "suicide" in the newspaper, without ever being the wiser that this was a demon who they could have dealt with by vanquishing him.
- Said word-for-word by Detective Mike Cellucci in Blood Ties to Henry Fitzroy after figuring out what he is. He says it with such disdain that Henry performs a Neck Lift on him in anger.
- Supernatural: Downplayed in "Fresh Blood". Gordon Walker was human when we first saw him, but he had to be turned into a vampire to make it okay for Sam to chop his head off.
- Snake's Revenge, the non-canonical NES sequel to the original Metal Gear, has Big Boss revealing at the end that he was forced to undergo a transformation into a cyborg in order to survive the injuries he sustained in the first game.
- Metal Gear 2 for the MSX2, the canonical sequel, parodies this by having a character gossiping that Big Boss may had become a cyborg and then subverts it by having Big Boss killed with a mere makeshift flamethrower.
- Nearly every antagonist human being in the second Arc the Lad game turns into a monster of some sort before fighting the main characters: Romalia turned most if not all of its troops into monstrous super-soldiers (granted, this was the only way to give them a shot against Arc, Gogen, Elc and their merry band of nearly unkillable warriors). Then the player realize that, thanks to its very liberal use of Mind Control Devices and other coercive tricks, most of the enemies the heroes killed were either drafted or had their free will destroyed, including the orphans turned monsters slaughtered by Elc & co in the White House laboratories. Twilight of the Spirits, the fourth game in the series twists the knife even more by showing that without Romalia's Mind Control Devices, the human turned monsters regained their full sentience and even were still biologically fully human and able to procreate with normal humans: in other words, the monsters were actually still completely human under their monstrous appearance, most of them were either drafted soldiers or helpless, terrified, and completelly blameless children used as guinea pigs by Romalia's scientists .
- Censorship laws in certain countries, most notably Germany, turn Video Games which originally had human opponents into this trope: the enemies look human, but it quickly becomes clear that they're not. And by "clear", we mean they palette-swapped all of the blood from red to green. So perhaps they're really Vulcans?
- Fallout 3. President John Henry Eden, crapshooting AI at your service. Not even a humanoid robot, just a monolithic computer with delusions of grandeur.
- Fallout 2. The Shi Emperor.
- Not that Fallout as a series has anything against good characters killing humans left, right and center...
- But only as long as it's in self defense (at least most of the time). Still, considering that out in the open wastes, essentially everything is trying to kill you, and preemptive strikes are a valid tactic...
- Especially if said humans are pretty scummy themselves, like the slavers of Paradise Falls.
- In Fallout: New Vegas, if you side against him, Mr. House qualifies, as the game classifies him as an Abomination rather than a human when you open up his isolation chamber and encounter his 200 year old shriveled up body, which you have to destroy to kill him.
- Subverted in Mega Man 2. In the final battle, Dr. Wily reveals himself to be an alien of some sort, but after defeating him you find that the alien was really just a hologram that Wily controlled from a machine in the corner of the room.
- This was originally planned to happen to Breen in Half-Life 2, revealing that he had become an immortal cyborg in the final battle. This was ultimately scrapped, although some fans speculate that he may have been turned into an Advisor.
- Played with in [PROTOTYPE], where it's revealed that the Alex Mercer you play as is just a pile of viral biomass that thinks it's Mercer; the real Mercer is long dead. So the hero, or at least the lesser evil was Not Even Human.
Alex Mercer: I'm not human. The revelation...it freed me. It killed me. I'm not human. *uneasy chuckle* Alex is just the role I play. Part of me was relieved...and part of me died. Just another disguise, right? So ingrained...so real...even I believe it.
- Of course, this is somewhat subverted by the real Alex Mercer being an even worse monster than the Blacklight virus despite being human.
- Sam & Max Season 1: The Big Bad Hugh Bliss turns out to be a colony of sentient bacteria.
- In Wolfenstein (2009), the evil General Zetta appears to have the ability to shoot magical balls of energy out of his hands and blocks bullets with his mind. Turn on your spectral vision, though, and you see he's really a giant slug monster; apparently being exposed to the Black Sun dimension turned him into a monster.
- Almost all of the human(oid) villains in Breath of Fire II reveal themselves to be some kinda of monster before they're fought. For example a Crooked arena organizer turns into a two headed humanoid wolf when challenged.
- Epic Mickey: Mickey and Gus get quite a shock when they find out the Mad Doctor has turned himself into a Beetleworx. He claims to have done this so that, when the Blot absorbs all of Wasteland's paint he will survive.
- The first Fire Emblem has the leader of the mostly human Dolhr be a huge monstrous Earth Dragon. He has a humanoid form but even that has a somewhat inhuman appearance.
- Quoted by Shepard in Mass Effect to Sovereign. (Full quote: "You're not even alive. Not really. You're Just a Machine and machines can be broken!"). Sovereign, being the vanguard of an entire species of MechaCthulhus, is unimpressed.
- Any doubt Heather had about killing Leonard Wolf in Silent Hill 3 is dispelled when it turns out he was not only an abusive father to the Big Bad, but also a giant fish person. Of course, it is later hinted that every creature Heather killed was human, no matter how monstrous, and that she had only convinced herself otherwise.
- Drakengard 3 puts this trope to disturbing effect in Four's DLC story. She set's out on Gabriella to shot down some pirate ships, only for it becoming clear upon arriving that it's ships full of elves who are desperately trying to flee. Gabriella calls out Four on this but simply get's the answer that since they are not human then all the more reason to shoot them down, since if they are not human then they have to be evil, and it is fine to kill evil people. All this ends up serving to make it perfectly clear just how twisted Four's moral code really is.
- Inverted in Digger, when the creepy figures with black speech bubbles serving a buried god are revealed to be ordinary living hyenas. This causes some complication for the surface-dwelling hyenas, since it means that a tribe member who was killed by the god's servants needs to be properly avenged, which requires some unusual Loophole Abuse to achieve.
- In Protectors of the Plot Continuum, Mary Sues are this, and often show signs of being Humanoid Abominations.
- In Worm the Endbringers were originally believed to be parahumans whose powers had twisted their bodies and minds into monsters. Tattletale realizes while watching Leviathan that they were never human. The same applies to Scion.
- Echidna was originally a human, but by the time she's killed her power has essentially consumed her. All that remained of Noelle were the memories and a grudge.
- The Siberian was a bogeyman due to being completely untouchable. The realization that she was a projection was a major shift in her perception and how she could be fought.
- A Batman: The Animated Series episode has people being replaced by robots. Batman doesn't realize until he pushes Bullock into a spotlight and electrocutes him. The commentary for the episode even points it out.
- In Teen Titans: Trouble in Tokyo, Robin apparently kills one of Brushogun's mooks. When he gets arrested for the act, he tries to play this angle without success.
Robin: But he wasn't even human!
- However, Robin's guilt is gone once it's discovered the creature was nothing but an animated drawing. Later, they are fighting the Big Bad's apparently human army of mooks... once a hit reveals them to be drawings as well, the Titans say "no need to hold back", and don't.
- Earlier in the series, the team fights armored agents of Slade, and later is shocked to find out that they're actually robots.
- This references an incident early in the New Teen Titans comic book. Starfire, newly arrived on earth and before learning the language, is involved in the Titans' action against some apparent drug smugglers: she blasts them to pieces. Tackled to the ground by Robin, she kisses him and learns the language. The point was that she casually killed several minor villains, who providentially turned out to be robots.
- In the 90s X-Men animated series, there were a few instances of Mecha-Mooks looking human at first, and the heroes having to pull their punches... until one got hit a little too hard, showed circuitry... and the heroes realized they could smash and bash at will. (Animated Wolverine loved discovering Mecha-Mooks, it let him act more like his comic-book self who got to slice up real Mooks.)
- Teenage Mutant Ninja Turtles: "Robots? Let's rock!"
- The newer incarnation has an even bigger shock than that when it was revealed that the Shredder was actually an alien squid inside a robot body.
- In the Nickelodeon series the Turtles have a lot of difficulty taking down a bunch of surprisingly tough guys in suits. Mikey only finds that they're robots when he's cornered by one and lashes out with his hidden blade in self defense. Once all the turtle s are aware that they're robots they're much easier to defeat. Inverted with the Footbots, the ordinary human members start quitting after being beaten by the turtles so often so they're replaced with robots, who conceal lots of saw blades and are tougher to defeat in general.
- The climax of the 94' animated BattleTech series is a No-Holds-Barred Beatdown between Major Adam Steiner and Star Colonel Nicolai Malthus; Malthus curbstomps Steiner's mech, Steiner fakes Malthus out with an empty escape pod, then Colossus Climbs Malthus's mech and sabotages it. During the ensuing replay with Good Old Fisticuffs, Malthus informs Steiner as to the meaning of the epithet he's been spitting for twelve episodes; Steiner is a "freebirth": born of a random match between individuals, where Malthus is a "truebirth": cultivated from carefully selected genetic material and gestated in a controlled environment. Steiner's response is to name the trope with disgust. He suckers the Designer Baby into grabbing a live wire and stands there watching him fry; then spares him and claims victory.
- This was the main topic of the penultimate episode of The Secret Saturdays 2nd season when it turned out that the Saturday's Arch-Enemy V.V Argost was actually a cryptid in disguise. Not just any cryptid either. He was in fact the same Yeti who slaughtered Drew and Doyle's parents and made them orphans.
- The Powerpuff Girls ostensibly-human enemy Roach Coach was dropped from a massive height, provoking a scared response about how it;s not okay for them to kill humans, then he's revealed to be an intelligent roach manning a human robot, whom they decide to keep in a jar.
- Warren T. Rat of An American Tail is the Mouse World variant of this. He''s not even a slightly-iffy rat, but an Always Chaotic Evil cat.
- Though cats are not quite always Chaotic Evil in this series, and also he doesn't get killed.
- Oogie Boogie from The Nightmare Before Christmas dies shortly after The Reveal that he's only a big colony of bugs pretending to be a person. With slight What Measure Is a Non-Human? issues, though, since those seem to be talking bugs anyway.