Was Once a Man



""I'm an insect who dreamt he was a man and loved it. But now the dream is over... and the insect is awake.""

- Seth Brundle, The Fly

Monsters are pretty damn scary. Horrible, bug-eyed, slobbering, and in no way ever human. Therefore, it's all the more unsettling when it's revealed that a monstrous creature (almost never the main character) was once human, but became a monster through some sort of infection, curse, sheer personal evil or transformation. And there's no means of changing them back.

Related to Body Horror and Face Monster Turn, but distinct in that while Body Horror deals with the fact of the monstrosity itself and usually follows it from beginning to end, Was Once a Man is where a creature is monstrous when first introduced, but is either implied heavily or later revealed to have once been human.

Sometimes the mind is not affected; only the body is. And sometimes the original mind can be reached. This does not undermine the horror of it. Indeed, in certain ways, it makes the horror even worse.

See also: Body Horror, Viral Transformation, The Virus, Tragic Monster and Stages of Monster Grief. Compare and contrast Uncanny Valley. Not to be confused with any tropes related to Gender Bender. Has nothing to do with the aftermath of particularly ugly Groin Attacks.

Anime and Manga

 * The manga of Chrono Crusade has an unusual example revealed towards the end:
 * In Xam'd: Lost Memories, it becomes clear fairly early on that both humanform weapons and Hiruko are former humans.
 * Each and every of the Awakened Beings in Claymore. And, perhaps more shockingly, the Abyss Eaters.
 * Every demon in the Berserk universe was once a human. Humans become demons when a creepy little egg-like item called a Behelit comes into their possession and they hit an emotional nadir where they will do anything to get out of their current situation. At this point, the Behelit rearranges the features scattered upon its surface into a human face and screams, which summons the demonic gods of the Godhand, who proceed to offer him the chance to become a demon in exchange for the sacrifice of those closest to them. It also turns out that . While demons do sometimes retain the personalities they had when they were human, all too often they commit Transhuman Treachery, becoming Complete Monsters of the worst order, with many of them preferring to dine on their former species.
 * Anna from Elfen Lied... Dear God, Anna.
 * King of Thorn has the "mother monster", which is eventually revealed to have been a human who succumbed to The Virus.
 * World Embryo - The enemy virus, Kanshu, were once humans who lost their memories and transformed into hideous beings upon listening to the infected radio signals in their cell phones.
 * Bleach. Every Hollow started out as a lost human soul. Eventually, it lost its heart, whether through time or the attacks of another hollow, and became a monster, feeling nothing but the desire to murder and a hunger for souls.
 * Similarly, the Akuma of D Gray Man. As with Hollows, their hunters know, at least in abstract that they contain the souls of innocent people forever tortured until the Akuma are destroyed and they're released, but only Allen has to confront the vision of them on a daily basis. As with Hollows (though in Bleach it's a different story), leveling up obscures more and more the original souls, until even Allen can't see them anymore. It also makes new souls in the process.
 * Some of the monsters in Sailor Moon, were (for the most part) originally human. Some of the Youma in the first season and the Pharge of the last season. Sailor Moon's power to restore the Pharge to normal actually shocks the Starlights, as they had to simply destroy them because they lacked the ablity to do so. (Though they implied their Princess could, as they stated they had to destroy them without her around). A single human-based Daimon also appeared in a flashback which was closer to their manga version.
 * Hakkai from Saiyuki.
 * Though he's not terribly monstrous or inhuman now, even in his demon form, and only really has to avoid it because the minus wave currently makes demons Ax Crazy.
 * In Puella Magi Madoka Magica, it turns out that, and to make things even worse,
 * In both the animes of Fullmetal Alchemist,
 * In both the animes of Fullmetal Alchemist,

Comic Books

 * Invoked in Strikeforce: Morituri with the "mutants", four humans who were accidentally turned into super-powered monstrosities when they underwent the Morituri Process without proper supervision.
 * In Camelot 3000, Morgan la Fay keeps an ape-like animal on a leash as a Right-Hand Attack Dog. At one point, she informs an underling that it was once a man, until he got on her nerves.
 * Galactus of the Marvel Universe was once a man of the previous universe named Galan. As his universe died to pave way for the new, current one, Galan journeyed into the center of the Big Bang refusing to give in to destruction. The powers that be were impressed and transformed him into Galactus.

Fanfics

 * Imperfect Metamorphosis: While never a man per se (on two counts), the blob monster (ie. ) definitely fits.
 * Final Stand of Death: Fusion Gundam used to be a that fell victim on Celebrity Deathmatch. They're a group of sentient Mini-Mechas fused with their souls, mixed with  wolf-like  humanoids. Luckily, they're no where interested in any Robot Wars, as they still have their human personalities.

Films -- Live-Action

 * In the horror film The Cave, one of the monsters bears the same tattoo on its hand as one of the cavers previously seen entombed within the cave system at the beginning of the movie.
 * in Serenity.
 * The Cenobites in Hellraiser films.
 * In the 1973 thriller b-movie Sssssss, mad scientist Dr. Carl Stoner (Strother Martin) turns his lab assistants
 * Darth Vader probably qualifies, certainly in spirit: He's more machine than man now, twisted and evil.
 * General Grievous certainly does... well, he was Once A Kaleesh, but you get the idea.
 * The lizard-monster in The Relic is revealed at the end to be a human explorer who ate a concoction of some particularly funky herbs in South America.
 * Davy Jones in the second and third installments of Pirates of the Caribbean. Lampshaded by Calypso, who describes Jones in this manner (and is responsible for the curse that transformed him).
 * The mutants in the Doom movie. Condemned criminals who were injected with an extra pair of chromosomes, but due to their DNA having "genetic markers for evil", horrifically mutated. And they can sense who else has the same evil genes, so they attack them as well.
 * Freddy Krueger from the A Nightmare on Elm Street movies. Once a human serial killer, he turned into something resembling a nightmare god after his death.
 * Vlad Tepes from the 1992 movie Bram Stoker's Dracula, apparently forsaking God turned him into a bloodsucking beast with power to turn others into vampires just like him.
 * Lost in Space: This fate happens to Doc Smith in the future timeline, when he is infested/mutated by spiders.

Literature
"He was not mad, as a man is mad. He had dwelt apart from humanity so long that he was no longer human."
 * The quote from the top of the page (now on the quotes page) is from The Beast in the Cave by H.P. Lovecraft, written at some point around 1908. Similar themes can be found in The Rats in the Walls, Facts Concerning the Late Arthur Jermyn and his Family, and The Shadow Over Innsmouth.
 * JRR Tolkien's Middle-earth (The Lord of the Rings, etc): As individuals, there are the Nazgul (once human leaders) and Gollum (once just an ordinary proto-hobbit). In Tolkien's concept, evil and the various Big Bads cannot create, only pervert: therefore almost every evil creature (e.g. those used as mooks) is a corrution or mockery of a pre-existing being. The orcs are descendants of elves twisted by Sauron's predecessor Morgoth. If you really want a squicky thought, it's rumoured that the Uruk-hai were partly Man in some fashion. Trolls are a mockery of Ents. Subverted in the case of the undead Barrow-wights, who only possessed the dead bodies of those buried.
 * In The Relic,.
 * In William King's Warhammer 40,000 novel Space Wolf, Ragnor is most horrified about the nightgangers that they find in a Chaos-tainted cave because they, or their ancestors, had been human once.
 * In Lee Lightner's Sons of Fenris when the Space Wolves and Dark Angels go up against Cadmus's elite forces, the tattered remnants of their uniforms is the only evidence they had once been human; some still wield weapons, but only those merged with their flesh.
 * In Graham McNeill's Warhammer 40,000 Ultramarines novel Dead Sky Black Sun, Uriel realizes the Unfleshed—monstrous, gigantic (next to him, a Space Marine), and flesh-eating—were once not only human but
 * In James Swallow's Warhammer 40,000 Red Fury, the Bloodfiends have fragmentary memories of the Blood Angels whose blood they have drunk; Rafen, fighting one, is reminded of his dead mentor Koris, and when he kills it, its last breath might have been a word: Brother.
 * Gav Thorpe's Warhammer 40,000 novel The Path of the Warrior reveals that Eldar Exarchs were once Eldar, but lost themselves in the struggle to control their rage and became part of a gestalt consciousness dominated by the first Exarch to lead their shrine, trapped and unable to die, subsumed into the whole, and speaking only in stream-of-consciousness.
 * In Star Wars: New Jedi Order, the mindless warbeasts known as the Vagh Rodiek were once Rodians. Then the planet fell to the Yuuzhan Vong.
 * Abeloth. She was once a mortal woman (species unclear) who served The Father, The Son, and The Daughter. She was eventually promoted to The Mother and loved her new family. As she aged, she grew paranoid that her ageless family would abandon her, so she drank of the Font of Power and bathed in the Pool of Knowledge. While this granted her immortality and advanced Force powers, this also mutated her into an Eldritch Abomination. Sadly, this event caused her family to abandon her.
 * In Neal Shusterman's Everlost, the monster called the McGill is revealed to have been
 * The Steel Inquisitors of Mistborn are humans who have been transformed into immortal killing machines via the dark art of Hemalurgy.
 * Also
 * In Book 5 of The Dresden Files, Harry gets a nice shock to the system when he looks into the eyes of the latest monstrosity to cross his path and
 * Played with in Discworld. Unseen Academicals marks the first appearance of  in the series. During the course of the book it is revealed that they are a manufactured species made from
 * In Robert E. Howard's Conan the Barbarian story "Red Nails", Tolkemec.


 * Also, Thak from "Rogues in the House." It's unclear whether he degenerated from humanity into his apelike form, or whether he ascended from apedom into something resembling humanity.
 * The Eldritch Abomination in Black Colossus
 * In the Gaunts Ghosts novel His Last Command,
 * In Pat Murphy's There and Back Again, Rattler, the cyborg Gollum-equivalent, was human until the Resurrectionists started experimenting on her.
 * All the monsters having once been human is a major theme and source of conflict in the Felix Castor novels.
 * In Terry Brooks' The Word and The Void series, demons are former humans who gave up their souls for power.
 * A brief part of Garth Nix's Old Kingdom series followed some sort of undead/free magic creature that used to be human.
 * Most of the various types of Dead were originally human in body and/or spirit (though some of the weaker ones, like the gorecrows, were once animals). Hedge starts out as a human necromancer, but becomes progressively inhuman as the Destroyer's power over him increases (thankfully, we never learn what exactly he was turning into, though it doesn't seem to have been Dead).
 * God-Emperor of Dune Leto II (mostly internally or to those close to him) laments his loss of humanity after becoming a giant Sand Worm, but he knows this is necessary for the survival of the human race.
 * Used in the Angel novel "Image", which has a guy who once was human but became more and more demon (and grotesque) in order to stay alive for hundreds of years.
 * Isaac Asimov subverts it in his story Eyes do more than See.

Live-Action TV

 * Several of the monsters on Supernatural, the most important being the demons.
 * One later iteration of the Daleks in Doctor Who were produced by "filleting, sifting, and pulping" living humans to render a handful of cells judged strong enough to be shaped into Dalek form and welded into a travel machine.
 * Another Dalek faction, the Imperials, were made from Human Popsicles. "Not pure enough in their blobbiness" indeed. And the original Daleks were once the humanoid Kaleds.
 * The Toclafane are Axe Crazy flying metal spheres that are able to deploy knifes and laserguns.
 * And of course the Cybermen, more than any of the others. It's arguably the whole conception behind the way they were originally written in the 1960s.
 * In the revived series, the Cybermen all look identical and have the same voice, so it's particularly jarring when Pete Tyler is confronted by a Cyberman that used to be  
 * Many stories involving The Virus: e.g. Mission to the Unknown. Inferno, The Seeds of Doom.
 * Poor little Jaimie from "The Empty Child" / "The Doctor Dances".
 * The Face of Boe may have once been
 * In Power Rangers Time Force, Frax, the robot who worked for Ransik but would eventually go solo, was once a human named Dr. Fericks who saved Ransik's life in the past, but was rewarded with the destruction of his lab and body. After using his own technology to rebuild himself, Frax vowed revenge on Ransik, and infiltrated his organization to bring him down from within.
 * Master Org in Power Rangers Wild Force was a Doctor before taking on the powers and identity of the original Master Org. His minions weren't happy when they found out, but he proved to be too much for them when they tried to rebel.
 * Zeltrax was transformed into a cyborg after a lab explosion. He is not happy about the loss of his body, and has decided that it is (in a roundabout manner) Tommy's fault. Mesogog was once a human scientist too.
 * In Power Rangers Samurai, Deker and Dayu were once human. Dayu sold her soul to save the life of the then-human Deker, but Deker has lost his memory and is now a Blood Knight who fights to satisfy his bloodlust, either by defeating a worthy opponent or by being put out of his misery.
 * All Borg in Star Trek started as other species, usually humanoid.
 * And Seven Of Nine is an actual human from the Federation.
 * on Lost claims to have once been a human before becoming  He's now human again, only able to switch between his monster form and
 * In the cult One-Episode Wonder series Heat Vision and Jack, the Cool Bike Heat Vision used to be Jack's friend Owen, before he got hit with an experimental ray gun that caused him to merge with his motorcycle.

Music

 * The eponymous character in the Black Sabbath song "Iron Man" was a well-intentioned human given metallic form by a "great magnetic field" while traveling time to save the future of humanity. He went on to because after he saves them, they won't help him or accept him.

Myth And Legend

 * Most undead creatures are, naturally, like this. For example: zombies and vampires.
 * In some Greek myths, Medusa was a priestess who was transformed as punishment for being raped by Poseidon in Athena's Temple (Athena, pissed that sex was going on in her temple, but unable to actually do anything to Poseidon, opted to punish Medusa instead).
 * Quite a lot of animals in Greek myth were actually humans who ticked off the gods and were transformed into beasts - Arachne and King Lykans being the two most prominent.
 * Scylla and Charybdis also fall into this category.
 * For a full list, read Ovid's Metamorphoses.
 * Fafnir, aka the dragon from Wagner's Ring cycle, aka the inspiration for Smaug in The Hobbit, Was Once a Man! In fact, he got the gold hoard first, and it cursed him for his greed.
 * ...his siblings, fyi, were a dwarf and an otter. No reason given.

Toys

 * in Bionicle . goes into Nightmare Fuel territory when you realize that Nuparu made the Boxor machines out of
 * Sorry, it had to be done.

Tabletop Games

 * A large number of Dungeons & Dragons monsters qualify, such as vargouilles, illithids (in which a larva eats your brain and uses your body as the foundation for its own), and skum. A number of prestige classes, such as the alienist and fleshwarper, eventually become something inhuman as well (and not in a good way, like a monk's ascension to outsider status), although without necessarily being evil.
 * In Mortasheen, this is the case with the Arthropoids, a class of creature made from humans fused with various type of insects ala The Fly. This also applies to several of the player races, like the Borg, the Sectillians and the Zombies.
 * The Necrons of Warhammer40000 were once a Sapient species, but every last Necron long ago had their consciousness uploaded into a robotic body. Among other things, this cost them their souls. Some Necrons have further from afflictions, be it the relatively simplistic method that was used to transfer most of the civilians into their bodies leaving them as little more but automatons, while the Flayed Ones have been driven mad by the loss of their mortal bodies, and seek to recapture the sensations of life by garbing themselves in the flesh of the living.
 * Also from 40k, the Haemonculi fleshcrafters turn some of their prisoners into Grotesques, massive hypertrophied things with iron plates fused over their faces and weapons grafted into their limbs. They are treated as Cannon Fodder in battle, and frequently used against their own species. Given how the Dark Eldar feed on physical and emotional anguish, it is quite likely that Grotesques retain their original minds but are trapped in bodies no longer under their control.

Videogames
"Talim: What are you? ...you're human, aren't you?"
 * All of the in Arc Rise Fantasia are heavily implied to be people of the  exposed to hozone without a  to protect them.
 * Those that aren't are implied to be the results of Ignacy's experiments on, including orphans.
 * Crewman Norris in Strange Journey. He begins hearing voices as you begin exploring Sector Bootes, and then he reaches for the sector's central tower, the Palace of Pleasure. Next time you see him, he's being experimented upon, and the transformation ain't pretty. Worst part is, you can see how he slowly loses his mind as you traverse the sector.
 * From the same company, the Hito-Shura. Ordinary High School Student one moment. Godslaying Badass Humanoid Abomination the next.
 * Of course, since Hito-Shura (the "Demi Fiend") is you, and the transformation is mostly glowing lines and an aversion of shirts, the actual level of change may be as little as being purely superficial. Of course, now you're a Physical God, assuming that you aren't killed by the many, many powerful enemies running around. Or at least have a backup save. Which is good, because
 * Virtually all the monsters from the Resident Evil series (with the exception of a few based on animals) are humans infected with various viruses.
 * The ghouls in the Fallout series. Apart from looking like corpses, they're not really very different from humans (they're more resistant to some drugs and they may live much longer), but some go mad, becoming Fast Zombie-esque "Feral Ghouls". Super Mutants are an even straighter example, as they actively kidnap humans to infect with the FEV (Forced Evolutionary Virus).
 * A specific mutant in Fallout 3 actually says word-for-word "I was once a man"
 * These things look - I think they really used to be people.
 * Dead Space. Every single zombie enemy you fight was once a human. The tentacle-baby monsters are implied to be embryos that were being vat-grown—possibly simply as an alternative to pregnancy, as it's demonstrated that the technology to grow limbs and organs independently exists in this universe.
 * City of Heroes has several, notably the Devoured,.
 * is definitely the worst case, being.
 * doesn't do it justice. It's
 * An in-universe theory toward the Thorn bloodline of Bloodline Champions.
 * This is fairly common in the Warcraft universe. Notable is the Demon Hunter Illidan Stormrage, who, after using a demonic artifact to gain power, was transformed into a demon.
 * Illidan's got nothing on, well, every race on Azeroth AND beyond. Firstly, those that play it strait:
 * Naga used to be Night Elf Highborn who were transformed by their queen, Azshara, when their city was sunk into the sea during the Sundering.
 * The Broken, the Lost Ones, and the Eredar are all degenerated versions of the Draenei who were mutated by over-exposure to fel energy.
 * The Forsaken were the humans who were stricken with a plague of undeath.
 * World of Warcraft also inverts this when we discover that . These are all inversions since the transformations go from "monster" to man.
 * There is a theory that Night Elves descended from Trolls who were exposed to the arcane energies of the Well of Eternity, once more inverting the trope.
 * All but a small few of the demonic races were once regular beings that became so tainted by fel energy they eventually became full demons, usually caused by direct interference by the Burning Legion as an assimilation plot. Many night elves became full demons in the form of satyrs and many other races became part way demonic such as chaos orcs and the felblood elves through similar corruption. The eredar are an odd case because the majority of them became demons after siding with the Legion while a minority fled and became draenei, which is different because the previous cases had mainly the minority of their race become demonic.
 * Only a few races like the Nathrazim are confirmed to be originally demonic.
 * In Halo: Captain Keyes, when you eventually find him. He's become absorbed into a massive Flood organism. And yet, retained enough sentience to contact you on your commlink only a few minutes earlier. Not to mention the fact that the master chief needs his neural thingywhatsit, requiring him to punch through what was left of his face into his brain.
 * Hell, any of the marines that flood infect could be an example of this.
 * Most, if not all, of the monsters from Clive Barker's Jericho.
 * Kokiri are said to turn into the race of skullkids when lost. They're usually shown as more tragic enemies, you being able to talk with them as a child in The Legend of Zelda Ocarina of Time.
 * The same game mentions that Hylians would eventually be transformed into Stalfos when lost in the woods. Not as creepy though.
 * All the NPCs in the Dark World of The Legend of Zelda a Link To T He Past, as the Dark World has the effect of transforming anyone who enters it into a form that matches his personality. Link is transformed into a rabbit without magical protection.
 * Similarly, the Twilight in The Legend of Zelda Twilight Princess turns normal humans into spirits, Link into a wolf (much cooler than a rabbit), and does not seem to affect magic-users. Spirits (and Twili) will eventually transform into the inconsistently named "Twilit Messengers" (better known as "those screaming things that guard portals").
 * Even better known as 'Those Bastards Who Sound Like The Iron Giant Being Beaten To Death And Refuse To Stay Dead For More Than Five Seconds'.
 * Described by the Freelance Astronauts as "Rastafarian squid-dudes".
 * Though they aren't actually monsters,  probably count.
 * Done in at least two side quests in Final Fantasy Tactics A2. In one mission, a requester asks for help as he and his friends are trapped in a mine and is afraid he will become the ghosts that haunt the place. When you get there, you encounter a gang of ghosts and its leader weakly begs for help.
 * In another mission, a requester asks for a Potion and Hi-Potion to treat some wounds/fatigue. When you meet the person, it's actually a zombie, but has retained enough sense and control to talk to Luso normally. When the zombie uses the Potion on itself, it winds up hurting itself and Luso has to stop it from drinking the Hi-Potion. That's when the zombie realizes it is dead and was wondering why clans were attacking and people at inns throwing rocks. Later on, you discover that the zombie is actually.
 * One of the gifted somehow turned into a dragon, originally being a hume.
 * Necrid in Soul Calibur 2


 * And for crying out loud, Nightmare.
 * Subverted in the next game, when
 * And, of course, Lizardman.
 * Raphael becomes infected with Soul Calibur's evil and becomes some sort of vampire-like entity.
 * Cervantes as a one time wielder of Soul Edge has been twisted into a ghost/zombie pirate.
 * Charade and SCII Berserkers also count.
 * Algol is another example.
 * Not literally a 'man' but close enough, Scorpiton from Patapon. He actually is
 * Stalkers in the Half Life universe are humans taken prisoner by Combine forces for acts of rebellion or "simply being in the wrong place at the wrong time", according to Alyx. Their organs and genitalia are removed and their blood replaced with a saline solution, a metal plate welded over their "face" and a strong implication that they are rewarded for good behaviour with artifical limbs so that they can walk. Brrr.
 * For that matter, the Combine soldiers themselves were once humans who have undergone memory replacement and had most of their organs replaced with cybernetic implants. The soldiers rise in rank by giving up more and more of their humanity. It's implied that all of the Combine's bio-weapons had similar origins.
 * Final Fantasy X does this a lot. All the Aeons were human, and an optional superboss is a monk named Omega whose hatred of turned him into a gigantic, four-legged monster with the power to create novae.
 * The most Disturbing/Saddest example however is Anima, who not only looked monstrous (a chained, gap-mouth giant corpse rising out a shell) but is
 * The fiends you fight in random encounters were once human souls. In fact, in the cutscene where the party reunites with Yuna in Home, you can see fiends forming from the souls of recently killed Innocent Bystanders in the background. And, of course, to top it all off, there's.
 * Pretty much everybody in Nexus War: Demons, angels, undead, and several others. All were once human and have become utterly inhuman. Just about the only characters that don't fit this trope are Eternal Soldiers.
 * StarCraft's Infested Terrans, which are a lot more open about it (since they're named, well, "Infested Terrans"). They're still horrific abomination suicide bombers, though.
 * In Quake II and Quake IV, the majority of the enemies you face are people who have been captured and forcibly turned into cyborgs. Some aren't even turned into troops, they just get their limbs hacked off and used as scenery (but they still twitch and bleed when shot). In Quake IV, this happens to the player character, and you get to see it happen, from his point of view. Curious?
 * In Knights of the Old Republic, rakghouls all used to be human before being bitten and infected. The player gets to meet some Outcasts and a terrified Republic soldier before they transform. Other parts of the EU use the rakghouls again, only this time there's a deranged Dark Jedi with a talisman that instantly transforms non Force-Sensitives into them. An old clone trooper holds out longer than most, but doesn't quite manage to kill her.
 * Also invoked to describe the unusual nature of Darth Nihilus. Although he's been implied to be a Negative Space Wedgie, or even the hero's Enemy Without. All depends on who you listen to.
 * Although not originally human, Sonic's were-hog form in Sonic Unleashed can be an example of the original mind/new body version.
 * The Archie comics give us a much straighter example in Jules.
 * Many Neopets characters like Edna the witch (now a green Zafara) and the Island Mystic (now a yellow Kyrii).
 * Rapture's Big Daddies are revealed to be this in BioShock (series).
 * (of BlazBlue: Calamity Trigger) Was Once a Person. Litchi hopes the original personality is still in there, but it doesn't seem to remember its previous life.
 * The trope's name was used word-for-word in Prince of Persia: The Two Thrones by the Prince to describe the giant, jawless boss he has to fight. And just like said boss, most of your enemies from the first and third game from the series are this.
 * The Many in System Shock 2. It's really unnerving to having your enemy viciously assault you while screaming for you to run away or put them out of their misery.
 * Silent Hill 3, possibly.
 * Dragon Age has the werewolves, more progressive ghouls, Broodmothers, and Golems.
 * Also, if the Chantry's teachings are true, the first Darkspawn were this.
 * The Dragon Age II DLC Legacy
 * Not truly a monster, but in Chrono Trigger, Frog used to be a human knight until being cursed with his current form. He doesn't let it get to him anymore.
 * The Heartless and the Nobodies of Kingdom Hearts are composed of different parts of of people. While most are mindless, some retain enough sentience and knowledge of their past lives to lament their fate.
 * Dawn of War: Dark Crusade invokes this with Macabee, an archaeologist who awoke things best left undisturbed and was turned into a Necron Pariah. When another race assaults the Necron stronghold, Macabee notes "I was like you, once, clinging to life and blind to the truth... deep in these catacombs, I was remade..."
 * Humans possessed and altered to fit their shape by the Prime Evils in the Diablo games, through Demonic Possession. Diablo's body turns back into that of the young prince in the first game when he's killed, and in the second, all the Three Evils are in the bodies of possessed humans, which turn more and more monstrous in irregular stages.
 * Parasite Eve 2 is a more nightmare fueled version than usual: every single one of the monsters in the game, which was a project intended to transform large numbers of humans into monsters.   This makes the monsters even more horrifying, since
 * Made even worse when it is revealed
 * In Wario Land 3,
 * Pokémon Black and White has the Ghost Pokémon Yamask, whose mask is its face from when it was human. Its Pokedex entry states that 'it sometimes looks at its mask and cries'.
 * Phantasmagoria: A Puzzle of Flesh reveals that.
 * The Black Knights in 11eyes underwent an Emergency Transformation courtesy of Misao. As Misao is the only one of them technically alive, she's also the only one that can change back. It doesn't help that they're wearing the monsters of the Red Night as a sort of living armor.
 * In King's Quest VI the Lord of the Dead was a man long ago, chained to the throne of the Underworld and enslaved as its ruler. The throne and his witnessing of unending tragedies slowly drained away the man's humanity and transformed him into something beyond comprehension.
 * In Dragon Quest IX,
 * In Portal 2, it's revealed that
 * In inFamous 2,  were once humans, transformed by  .   himself can also change into a gigantic monstrous form.
 * In the Game Boy Advance and PSP versions of Final Fantasy IV, Cecil's trial in the Bonus Dungeon includes a potential encounter with a Goblin who insists that he used to be human, and that the curse on him will wear off shortly. Indeed, if you don't attack him, the battle automatically ends and a man is standing where the Goblin was (killing the Goblin causes Cecil to fail that part of the trial, of course.)
 * In Super Robot Wars Z 2: Hakai-hen, The Dimesional Beasts
 * All of the main characters in Final Fantasy XIII are normal humans who were turned into.
 * Version 6 of Ao Oni has all three of the four main characters converted into one of the monsters when they were killed.
 * At the end of Magical Girl Lyrical Nanoha A's Portable: The Gears of Destiny,, is revealed to have once been a human named Yuri Evelvine.
 * The Elder Scrolls V: Skyrim has the Falmer, former Snow Elves who after losing a war against humans sought refuge with the Dwemer, a technologically-advanced race of underground elves. Despite their early hospitality, the Dwemer suddenly turned on and enslaved their kin, feeding them strange mushrooms and torturing them for their amusement. Not only did the Snow Elves degenerate into something like Morlocks, but what the Falmer went through fundamentally changed their very souls; theirs can be trapped in normal soul gems like any other beast, while sentient beings like humans or elves require black soul gems. The Dwemer literally devolved the Falmer into animals.
 * A major part of the Reapers' modus operandi in the Mass Effect series. It begins with their Husk grunt troopers in the first game, which are augmented by variations and husks made from alien species in the others. But the crowning achievement is the revelation in the climax of the Suicide Mission that.

Webcomics
"Karnak: [dramatic slaughter montage, final panel thought bubble] I hate this place."
 * The page image is from Nedroid, "Face It".
 * Bog Leech: I was two men!
 * Demons in Dominic Deegan Were Once Men; we get to see some of the transitions. Most notable, of course, is, whom we knew rather well before his death. From this to this to this.
 * Then there's Karnak, who is revealed to have been human near the end of the Ecstasy & Evil storyline, very casually by a former friend who has apparently given up even being sad about losing him. His back story is fleshed out as the comic progressed, and so far the only really bad thing he ever did in his life he repented halfway through and ran away to sacrifice himself heroically. May be the only being in hell not rightfully damned there.
 * Demon Karnak, however, is both evil and a total Jerkass, although he has been having some character development. Had a Rorschach Moment in December 2010 and appointed himself Warden of Hell and informed the damned that they were all trapped in there with him.
 * Without becoming much less despicable, Karnak in the last couple years has scaled the heights of Crazy Awesome. His Siggy-flail was choice, as was his "The Reason You Suck" Speech at his Kangaroo Court trial. And then there's the simple things:


 * A more typical progression of this is probably provided by Lady Loxo, who used to be soulbound to the Demon of Treachery back before Karnak exploded Hell into submission, and who becomes all serpentine and scaly after beginning to consume souls out of the 'feeding pits.' Bulgak Adrak is much more conflicted and his transformation doesn't progress nearly so smoothly, even once he gives in. Then he has an epiphany and his soul explodes.
 * Then there's TIM, the eyeless, nameless infernomancer who provided the first evil in the comic and kept coming back with new levels in Body Horror.
 * This trope is not applied to benevolent synthetic entities like Quilt and Acibek who were made out of unwilling human victims. Political Correctness Gone Mad, possibly, but while the Acibek thing was tragic and the Quilt thing creepy, the focus is intentionally on who they themselves are, not their antecedents.
 * Jacob Deegan, in his extremely long 'quest to become The Zombie Alive' phase, is explicitly trying for this effect as hard as he possibly can. The universal Squick is a perk.
 * Addressed in The Fancy Adventures of Jack Cannon; as a combined punishment-and-strategy, Frankie is turned into a monster, shaped roughly like his old human self, but bigger, stronger, and uglier, with glowing red eyes. Gavin remarks that the eyes were a mistake; they made him too monstrous, making him easier for Jack and his family to deal with. Gavin restores his original human eyes so that the next time they make him fight someone, his opponents will be thrown off balance.
 * El Goonish Shive has Aberrations. We've only met one on-screen, but he no longer looks human. At all.

Web Originals

 * The SCP Foundation's  (squick warning) as revealed in the uncensored report.
 * in Ruby Quest
 * According to his song, Trogdor was originally a man, but then turned into a dragon-man before finally becoming a dragon completely.

Western Animation
"ChickenFoot" "I was once a man, like you! I once worked in a Chicky-Licky hut, like you!" Dib: "I don't work in a Chicky-Licky hut." ChickenFoot "DON'T LOOK AT ME!""
 * The creepiest part of Ben 10 Alien Force is the revelation that the DNAliens were all once humans who had brain slugs put on their heads. It's never really addressed after "Max Out", which was the most serious and darkest episode of the entire series, though.
 * Except for one where an amnesiac man who can only recall being taken by the aliens turns out to be a disguised DNAlien and is restored to being a human again at the end of the episode.
 * In one episode of Invader Zim ("Gameslave 2"), the rat people in the labyrinthine parking complex Dib gets lost in claim this happened to them, but Dib is unconvinced. A female one actually says "I was once a man," causing Dib to respond, bewildered, "But... you're a woman."
 * Also, from "The Sad, Sad, Tale of ChickenFoot", we have this:


 * For those not in the know, ChickenFoot is actually
 * Parodied in Sealab 2021, in which a talking tree cobra claims "I was once...a man!" before saying "Just kidding, I've always been a snake."
 * After Cobra Commander gets hit with altered fungus in G.I. Joe: The Movie and starts turning into a snake, all he can hiss is "I was once a man!" until the transformation is complete. Definitely the Trope Namer and what Sealab referenced in the above quote, despite not being "human" in the first place in this continuity.
 * Although he got somewhat better in the series immediately following the movie with some assist, which justified in story the Power Armor he wore.
 * Windfang, Wrath-Amon's literal Dragon from the animated series Conan the Adventurer. Once a famed general, he was taken prisoner during a battle in Stygia and transformed by Wrath-Amon. His wife-to-be ran from him in horror, leaving Windfang with nothing but 200+ years of servitude to the evil wizard.
 * Generator Rex. After the Nanite event, every living thing was infected by nanites. Many EVOs were human at one point. And any one can go EVO at any time. And the only one who can cure them is a teenaged boy, and sometimes not even then.
 * About half of the mutants in Street Sharks, with the other half being sea creatures-turned-mutants. The good news is that the mutations pretty much can't change one's free will, so fewer humans are gradually transformed by the Mad Scientist.
 * Not true...the bad guys' working on a formula to make them under his control. He just keeps having the test subjects escape...
 * The Big Bad, Skeleton King from Super Robot Monkey Team Hyperforce Go!! was once a kind-hearted man called the Alchemist, who in fact was the one who created the monkey team to combat the monster he became. What makes his case really sad was that his transformation wasn't by choice.
 * In an episode of Futurama, Leela encounters an octopus-like creature in the sewers that claims (in a deep, growly voice) that it "used to be a little blonde girl named Virginia".
 * In the Adventure Time episode "Holly Jolly Secrets", it's revealed that
 * In an episode of the 1990s Silver Surfer animated series, the Surfer and a group of researches come across an enormous green blob monster on a universal library planet built by Precursors. It's the precursors (and the crew of a pirate ship) themselves after they devolved into this form and linked up with each other in a hive mind of knowledge.
 * Played for Laughs in the Looney Tunes short "Mutiny on the Bunny". A horrid-looking and clearly insane man runs down the gangplank from Yosemite "Shanghai" Sam's ship and has just enough time to turn to the audience and declare "I was a human being once!" before running off screaming into the night.