2000 AD: The premise of The Visible Man is of an ex-soldier who gains partial Invisibility from a freak accident involving nuclear waste so that all his internal organs are showing. People shriek in terror at the mere sight of him.
Art Ops: Scarlett infects several works of art (specifically, Michelangelo's David, Cherubs from Raphael's Sistine Madonna, and the Statue of Liberty) with a disease that deforms them into lumpy monstrous versions of themselves.
Anyone who gets infected with The Beauty will have their body changed to become conventionally beautiful. 800 days later, they spontaneously combust from the inside.
Anyone who gets the cure for The Beauty, like Detective Vaughn, ends up looking like a severe burn victim.
When Warren Mears is brought back in Season 8, he's still without skin. It goes From Bad to Worse when Buffy destroys the Seed of Wonder, wiping out magic and negating the spells holding Warren together, causing him to collapse into a pile of gore.
Mohra Demon blood has regenerative powers, which was being sold to injured humans. As a result of magic being gone in Season 9, the blood has a nasty side effect of causing unstoppable cell regeneration. Those exposed to it started to grow giant tumors all over their bodies that wouldn't stop growing.
Cla$$war: "Uh ... it appears my left leg has just eaten your dog."
Demons in Clean Room can permanently mold the flesh of their host. This is used for visceral effect either on bystanders or the host post-possession. Specific examples include folding a man into a human pretzel (and swapping one of his hands), spinning a man's face upside down, and rebuilding a man's head into a semblance of a horse's.
The Crawling King: In one story, a woman puts on a ring, and then her skeleton exits her body through her mouth. It then takes the ring and leaves the woman a lump of flesh on the floor.
Unsurprisingly, EC Comics had a copious amount of it throughout their horror titles, usually the result of people seeking shady medical treatments.
The Tales From The Crypt story "Bats In My Belfry" follows a man who fears he's going deaf. He seeks out a mysterious doctor who provides transplants from animals to humans. Of course, he gets a bat's echolocation and the rest of the comic has him slowly transforming into a human-bat hybrid, then feeding on his conniving wife and her lover when they plot to murder him.
From Vault Of Horror, "Strictly From Hunger" has a poor schmuck named Pete approach a hermit witch to cure his terminal cancer. She casts a spell that will ensure he won't die. Unfortunately, this allows his cancer cells to run rampant through his body and he gradually mutates into a flesh-eating blob that the townspeople have to bury in a cave-in because it can't die.
Haunt of Fear's "Horror We? How's Bayou" is about a pair of psychopathic brothers who lure travelers to their hut and dismember them. After a doctor becomes their latest victim, the remains of the unfortunate the brothers dumped in the swamp coalesce and rise as vengeful zombies with their body parts horribly mixed up. They than find the smarter of the evil duo...and give him a twisted surgical makeover with the dead doctor's equipment, turning him into a suffering, mangled abomination of dislocated parts.
The same issue also has "Gorilla My Dreams", where a businessman is kidnapped by an insane doctor who transplants his brain into the body of a gorilla. When the gorilla man wakes up, he's obviously terrified to see his human corpse lying across from his new body, and his thrashing gives the doctor a fatal heart attack. Eventually his former body is discovered and his family believes the gorilla killed him. In the end he opts to join a travelling circus and his children visit to yell at him for murdering their daddy. Apparently this story was an inspiration for DC's own tragic monster hero, Swamp Thing.
In Eight Billion Genies, a woman who makes a wish to "be one with the sea" is turned into a gigantic squid/whale/fish/mermaid creature as a result. She is thrilled at first as it allows her to freely explore the ocean, but eventually gets lonely...
In Enigma, several comic book villains come to life... as more horrifying, mutated versions of their more light-hearted comic forms. And each of them starts out as a normal human. Granted, they're not all terrible, but the first guy got it pretty bad. And then there's the Enigma's own mother, who does this to herself in a fit of apparent insanity, and takes it up to eleven.
The second issue features a man who has been engineered into a killing machine. His body is half gone. His cock has been connected with the parts of his brain that spark up when he kills things. He's still sentient... but just barely.
In the ninth issue, a Frequency agent investigates a medical facility dealing in top-of-the-line stem cell research that's cut off all communications to the outside world. Turns out the doctors went insane from the gas leak and decided to build a temple to the wonder of the human body. Using all the patients as bricks, and the stem cell technology as mortar. And they're all still alive.
Henchmen: When talking about the Supervillain Microwave, Weasel mentions a man named Twin-Headed Tim, so named because of an apparent massive goiter he had on his neck. The thing is, it's not actually a goiter, but the result of working as Microwave's personal assistant for three years, and in that time, being exposed to the low-level radiation that Microwave constantly emits.
Widespread in the nuclear war wastelands (known as the "cursed Earth") with rampant radiation-induced deformities.
Also common in Mega City-One, where people willingly inflict body horrors on themselves, such as The League of Fatties, whose sporting events include extreme eating and fat contests (the fattest person wins 50,000 creds and tons of endorsement deals).
Explored in Judge Dredd (reprinted in Complete Case Files volume 4): "ugliness products", i.e. skin mold cream, tooth decay gel, dead skunk aftershave, etc., that are popular in a society in which any nonmutated human could achieve beauty.
There are two Judge Dredd stories dealing with humans being mutated into a giant spider. One is told in a tragic manner concerning a woman. The other is told in a comedic manner with the victim being a man.
In King City, users of the drug "chalk" eventually turn into more chalk. In both cases we see on-page, it starts with the hands. This is what eventually does Max's old war buddy Tooth in; by the time Max gets there, the hazmat crew/drug dealers are hauling him off and all that's left is a Chalk Outline.
Rat-Man combines this with Gory Discretion Shot. Janus Valker gets hold of a device that allows travel in parallel dimensions, but that one is malfunctioning and manages to materialize every other Valker in existence simultaneously inside the body of the first one. We only get to see an arm erupting from Valker's own arm before cutting to Rat-Man and his friends witnessing it. Their horrified faces and the narration are more than enough.
The revivers of Revival have a Healing Factor and reduced emotional connections. This allows several of them to engage in self-mutilation for fun and profit to the horror of their loved ones. Examples range from ripping out one's own teeth to severing an arm and sharpening the exposed bone as an improvised weapon.
The Dragon has on many occasions portrayed the healing factor of the title character this way. In a particularly strange example, Dragon had the mood spoiled during sex when he and his girlfriend are horrified by the sight of his severed arm suddenly and unexpectedly regenerating in a gruesome fashion. Another one was when he was beaten within an inch of his life and left stuck in a chimney, so he couldn't move and all his broken bones would set wrong. It was not a pretty sight.
Other examples of Body Horror come from some of the villains from Dragon's rogue gallery. For instance the Doctor Octopus expy with real squid tentacles growing from his stomach (including a beak) or Openface, whose entire head splits vertically to reveal rows of sharp teet and a freakishly long tongue. Then there's a guy whose entire skin turned invisible so his organs are showing, exactly like "the Visible Man" example above. The list goes on.
The Simpsons: Played for laughs in several Treehouse of Horror comics. The most notable example is "Sideshow Blob", where criminal Sideshow Bob (who has a bad cold) is injected with the wrong vaccine by Dr Nick Rivera and turns into a rampaging blob monster.
Spawn: Al Simmons, the main character, was set on fire as he was killed and is shown to have severe burns all over his body, including his face, because of it.
Stone Island. Harry's transformation into one of the creatures, which starts with him puking his guts out and doesn't stop until he's a seven-foot-tall monstrosity with no eyelids, a permanent grin in a distorted face, and a hideously lengthened skull.
Stormwatch: In Warren Ellis' writing, the Island of Gamora launched a watered-down superhuman mutagen upon an English town. Most victims were rendered as horrifically mutated corpses. The unfortunate survivors were fused into a giant mass of flesh whose hands were fused together in a shape similar to that tubular seaform known as a lamprey.
Transformers: Generation 2: The Cybertronian Empire boosts its population via Budding, a long-hidden method of Cybertronian reproduction. We see what the process entails at one point: the surface of the "budder" practically comes alive, and slowly forms into a living mechanical foetus, which tears itself free of the host body. While this is happening, the first mechanoid is writhing in pain and discharging all kinds of energy.
The Transformers: More than Meets the Eye introduces Empurata, a technique employed by the old and corrupt Senate. Basically, they have the head and hands of the victim removed and replaced with boxy cycloptic heads and claws or clamps for the hands. A few of the big named characters suffered this, notably Whirl and Shockwave.
Wildstorm: World's End: The Warhol virus is named so because it keeps the victim alive for about 15 minutes while the victim is turned into a hulking, disfigured maniac.
Yummy Fur has such delights as the author eating his own snot (which he has admitted to doing), a man's hand spontaneously falling off, Ed the Happy Clown's penis growing a miniature talking, thinking Ronald Reagan head at its tip, a man who shits so much that he suffocates himself and many others, graphic scenes of penis surgery and so much more. Chester Brown himself, by all accounts, has a very amiable, mild personality.
