The Virus

Well, that bites and sucks.

"Jesse is dead! You have to remember that when you see him, you're not looking at your friend. You're looking at the thing that killed him."

— Giles, Buffy the Vampire Slayer

The Virus turns people into itself or into entities subservient to itself. The transformation is both mental and physical. The converted will have unflagging loyalty and be instantly ready to commence villainous actions. Expect it to try to cause The Plague.

If the converted still remember their previous selves, they will use their personal knowledge to prevent their former loved ones from doing them harm, or from trying to get them back. Despite the body snatching, if The Virus is only able to crudely mimic human behavior it may lead to a Glamour Failure that's especially noticeable. Some strains of The Virus are so powerful the infected can even mutate environments. This tends to lead to the Womb Level and Organic Technology.

How much of the former person is left after infection depends on the series, as does whether or not the process is reversible. It also depends on whether it's a main character or not, they can sometimes use The Virus' powers against it with enough Heroic Willpower (a property more typical of The Corruption) and even play Sheep in Wolf's Clothing for a while. If it's one of the main villains using villainous willpower, then they tend to end up on the high end of the Elite Zombie chain. Though it's equally likely for the villain to overestimate their ability to do this and self infect, only to discover their Transhuman Treachery ran smack dab into Evil Is Not a Toy. If The Virus is sentient, then more often than not it is also a Hive Mind with a Hive Queen directing it.

Stories of yesteryear often tied this symbolically with the Red Scare; nowadays if it represents something, it's The Heartless. The lowest common denominator for man to sink to, susceptible when one lets their own Dark Side take over — and it takes people around them down, too.

Often how humans become something much, much more horrible.

Sometimes overlaps with Virus-Victim Symptoms in cases where the host enters a zombie-like state before being completely consumed. Compare Viral Transformation, where a similar change does not cause a Face–Heel Turn. See also Puppeteer Parasite, Festering Fungus, Clone by Conversion, Face Full of Alien Wing-Wong, Contagious A.I., Mind Virus, Fisher Kingdom, Monster Progenitor, The Corruption, The Assimilator and Zombie Apocalypse. Commonly represented with Tainted Veins or a Red Right Hand. Nearly always a Snowballing Threat as it accumulates victims. When the virus itself is portrayed as a miniature monster, rather than turning its victims into monsters, it's Monstrous Germs.

Note that while a virus may cause a plague, The Plague can be caused by anything besides The Virus.

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Examples:

Anime & Manga

• Blue Drop has a somewhat lesser example. The second manga, Tenshi no Bokura, implies that any human female sexually exposed to the One-Gender Race Arume (a species of alien lesbians who reproduce by a complex-and-imperfect genetically engineered Homosexual Reproduction process) becomes psychologically incapable of loving a man, possibly due to special pheromones (a form of chemical warfare?). The implications for both species, as well as the results for society, are truly horrific.
• Cardfight!! Vanguard:
  • The manga introduces a superpower known as PSYqualia that is later exploited by the Big Bad to transform people into "PSYqualia Zombies" under his control. The virus is spread via Cardfights, as being defeated by a PSYqualia Zombie transforms the loser into another Zombie, giving them a Superpowered Evil Side with a side of Brainwashed and Crazy. The goal of the Big Bad is ultimately to exploit PSYqualia's control over destiny by creating a critical mass of Zombies under his control, then using their collective gravitational power to rewrite the laws of the world itself.
  • The anime (which at the time had Overtook the Manga) introduces its own version during the Link Joker arc called "Яeverse". Like "PSYqualia Zombies", the Яeverse virus spreads through Cardfights and slaps their victim with a Brainwashed and Crazy Superpowered Evil Side and subservience to the Big Bad of the arc. The real-world card game mirrors this storyline through the introduction of corrupted "Яeverse" versions of existing cards, which depict the corruption with varying degrees of Unwilling Roboticisation.
• Cells at Work! features a literal example! Actual viral infections are depicted as hats, masks, and other artifacts that latch onto healthy cells and brainwash them into making more and spreading them around.
• Digimon Adventure 02: The Dark Spores are spread by Milleniummon to harvest the darkness in people's hearts. It's effects are closer to More than Mind Control than traditional but victims still turn into smug snakes.
• GaoGaiGar: Zonder Metal, which can corrupt organic lifeforms as well as cyborgs and sentient AI into mechanical monsters.
• In Guyver, the Zoanoid Aptom eventually gains the ability to infect other Zoanoids, then absorb their biomass, and is able to make duplicates of himself.
• JoJo's Bizarre Adventure:
  • Stone Ocean: After Weather Report regains his memories, his Stand transforms into Heavy Weather that subconsciously creates rainbows that contain subliminal messages making people who look at the rainbows and touch them turn into snails. The transformed snails also actively seek out other living organisms and contact with a snail also initiates the transformation.
  • Steel Ball Run: Ferdinand's Scary Monsters lets him transform people and animals into dinosaurs by touch, and anything that the dinosaurs wounded will also turn into a dinosaur, a process that can be infinitely recurring.
• In one chapter of The Kurosagi Corpse Delivery Service, a real-life parasite that infects snails begins to infect humans instead, with art that puts the horror back in Body Horror.
• Le Chevalier d'Eon: People being controlled by the Psalms turn into "ghouls" who bleed silvery blood and their flesh is all gross-looking. They don't seem to have control over their bodies, though in typical fashion the "infected" may have some dying words such as "kill me" to mutter.
• Mobile Fighter G Gundam has DG Cells which prove that the only thing worse than zombies are cyborg zombies with giant robots.
• Red Garden: In the first episodes those affected by "the virus" appear to be superhuman. One of them also walks like a dog. Consequently, it ends up being a curse. Two rival clans, Dolores and Animus, each stole from the other a Book Of Curses and used it against the other. The protagonists' boss works for the Animus clan, who cursed people of Dolores descent to turn into mindless and feral killers. The way it manifests still acts like this trope, however.
• Uzumaki: The Spiral infects people to spread insanity and death.
• Venus Versus Virus: The Virus changes humans into demons.
• World Embryo has the Kanshuu. Traveling through cell phone signals, any person who listens to their phones and hears these signals mutates and contorts into another Kanshu. It gets worse since anyone who knew those victims in life, be it parents, friends, siblings, etc., will have their existence completely wiped from their memories, causing them horrible mental trauma.
• Yu-Gi-Oh! GX: The Light of Destruction is more typical of The Corruption when it comes to Yubel but it'a certainly this trope for others it affects.
• The zombie plague in Zom 100: Bucket List of the Dead appeared out of nowhere, upending all of Tokyo in the span of a single night before Akira got up in the morning. It's spread via biting and turns people into Flesh-Eating Zombies who chase after loud noises and human smells. Its rate of infection is also inconsistent. Some people turn immediately after a bite, while others change painfully slowly or get bitten multiple times before turning or dying.

Asian Animation

• Happy Heroes: Season 5 is about Big M. and Little M. exploiting a virus from Planet Gray that remains latent in an infectee until it's manually activated by a person. Once it's activated, an infected individual becomes mind-controlled into becoming a villain, working for Big M. and aiding in his effort to take over Planet Xing.

Audio Plays

• Big Finish Doctor Who:
  • The Eminence is a Deadly Gas being that kills anyone who breathes any part of it in and converts them to a soulless, deathless soldier impervious to damage.
  • The War Doctor audios have the Vaarga Plants return, now with the ability to turn Time Lords as well — and even regeneration won't save them.

Comic Books

• Beast Wars: Uprising:
  • The G-Virus, the last remains of Galvatron, which turns anyone it touches into a duplicate of the former Decepticon leader, winning personality and all. During Micro-Aggressions, Grimlock has it stolen so he can try and turn the Builder higher-ups into immobile Galvatrons, ending the Uprising. Hot Rod tries to stop this on the grounds that it would also infect the still very mobile Micromasters, Maximals and Predacons nearby as well. Unfortunately for everyone, a Micromaster was already infected during the Virus' theft, and while everyone's busy, turns into Galvatron and escapes into the night.
  • In the finale, the Builders are pushed to desperation by the Resistance. They unleash the Vehicons, who infect Cybertronians with a virus that removes their spark and turns them into more Vehicons. Within a few days of being unleashed, they manage to take 70% of the planet. Then it turns out they can infect Autobots and Decepticons too. It's all part of their creator's plan to remove the spark of every living thing on Cybertron.
• The DCU:
  • The O.M.A.C. from Infinite Crisis are complex nanomachines that hide in a person's body until they are kickstarted through a command by Brother I. They proceed to take over the inhabitant's body and turn him into one of the electric blue, one-eyed killing machines. Ironically, they were spread through tainted flu shots.
  • The "Legion of the Damned" arc in Legion of Super-Heroes post-Zero Hour features the Blight, which ravages the United Planets and takes over most of the Legion before the remaining Legionnaires manage to purge it.
  • In Final Crisis, Big Bad Darkseid uses the Anti-Life Equation this way, bringing Earth under his control, and transforming some of the heroes into his monstrous servants. Ironically, Checkmate uses the millions of people infected with OMAC nanotechnology left over from the last crisis in order to fight against the Anti-Life Justifiers, making this a Virus versus Virus situation.
  • The Anti-Life Equation is used again in the Elseworld series DCeased, in which Darkseid uses Cyborg to pass it along as a digital virus of sorts, but it instead turns them into rampaging zombies. Darkseid ends up nuking Apokalips when he's infected, Desaad sends Cyborg to Earth where he proceeds to infect the world.
• Marvel Universe:
  • The symbiote worn by Venom (and Carnage, and other "spawn") can be a Virus that can overrun whole worlds if left unchecked. The Silver Surfer encountered a world whose entire population had been taken over by them while still a Herald of Galactus, and it is hinted that this was not the only one where it happened.
  • The Brood from X-Men reproduce by infecting living hosts and converting them into more Brood. They assimilate the unique traits of the victim in the process — for example, if they infect a mutant, the resulting Brood would gain that mutant's powers.
  • During the "Operation Zero Tolerance" arc of X-Men, Bastion turned certain people into "Omega Sentinels" by abducting them, filling them with nano- and cybernetics, and placing a sleeper program in them that would activate in the presence of mutants.
  • This is the power of Weapon XII, a villain appearing in New X-Men #129-130. Every person or animal he touches develops glowing eyes and permanently becomes an extension of his mind. By the time Xavier and Jean Grey arrive to deal with him, he's infected most of the humans in the Chunnel, several hundred of Multiple Man's bodies, and a collection of birds, bats, and dogs.
  • Marvel Zombies features a zombie virus that infects superhuman beings, who then devour the rest of the population, until their hunger leads them to travel to other planets and eventually other universes, seeking more food and infecting more superbeings in the process.
  • The classic Techno-Organic virus and the Transmode virus from X-Men both qualify as this, warping their subjects into Humanoid Abominations (if they're lucky) or minor league Eldritch Abominations (if they're not). The former requires Cable-level Psychic Powers to hold in check, or Apocalypse-level shapeshifting powers to control (a weaker shapeshifter who got infected became the horror-show known as Metus). The latter goes beyond the laws of nature to the point where it can resurrect the dead, as demonstrated in the Necrosha arc.
  • Ultimate Vision: Gah Lak Tus has one that turns people into purple monsters that do his will.
• One arc of Powers revolves around a dangerous and addictive superpower (can anyone say "drug addiction allegory"?) that is spread between people, infecting new users.
• In The Smurfs, there's a kind of fly that carries a Zombie-like virus.
• The second major arc of Sonic the Hedgehog (IDW) is about Dr. Eggman unleashing a virus that turns the infected into robotic zombies, or "zombots". It's designed to speed up the infection rate with further physical contact [fighting zombots] and is extremely contagious on any organic matterial by a simple touch. Sonic himself is infected, and a major part of the arc is him trying to fight the transformation's spread.
• In the French comic Zombillénium, an amusement park run by monsters has a staffing problem. Two managers (a werewolf and a vampire) bite a new guy so he can fill a gap as that monster, but as they keep arguing over who gets him, they also keep on biting him to assert their hold. He ends up turning into a Big Red Devil instead, and ends up being the star attraction.

Fan Works

• Abraxas (Hrodvitnon): The Many are basically what you'd get if the Flood had a baby with the Thing. They're a viral Undead Abomination which can infect and assimilate living and dead creatures, merge their bodies into various new constructs, and merge the hopelessly-insane remnants of their consciousnesses into the Many's collective Hive Mind.
• In Divine Blood, Kodachi Kuno is this via Agent Smith style Mind Rape targeted at anybody with mental powers or borrowing mental powers via a spell. She mostly targets her own mass-produced biological daughters early on.
• The Eleutherophobia fic The Thing from Another World centres around a crashed Skrit Na ship. It turns out that everyone on board was killed by an alien pathogen that causes people to become violent cannibals. When Tom and the Animorphs enter it to investigate, Marco gets infected.
• Felixs Guide To Apocalypse Survival is centered around this, with Carol creating a pathogen that turns people into clones of herself. No surprise, considering that this was inspired by two things.
• Beitus in Hackbent (a.k.a. Lutark Lampri) is literally this, but a variation of it. He touched both Rodard and Haeton in his disguise instead of in his real form, and at the moment, it isn't obvious they're infected. (The actual infection is shown later.) He uses way more hidden form of this trope, but after he erases his own disguise, it's become more clear to see, like when he infects Skaia. What's also rather unique is that Beitus is able to choose how the infected will behave. While Haeton's only line when infected is "Join us", Rodard became a Deadpan Snarker and a Minion with an F in Evil.
• In Mega Man: Defender of the Human Race, a virus that destroys robots' memory cores is the crux of the Conduit's Evil Plan.
• The planet Nemesis in Metroid: Third Derivative. Being the source of all Phazon, it spawns Phazon meteors which are thrown into space and affect other planets. Phazon in high doses is lethal to any living beings that comes into contact with the material, though slow exposure can increase tolerance, increase the probability of body mutations, and decrease the probability of death by Phazon.
• People Turning Into Smith Clones follows a group of bluepills trying to survive the Smith virus.
• In Project Tatterdemalion, Hollows are the result of an alien Synthetic Plague called "Madsen's Hollow". It transforms one-fifth of the infectees — those with all of a set of genes that make them vulnerable to it — into monsters with Combat Tentacles and a drive to infect others to reduce their loneliness. The other eighty percent die messily from the incomplete effect. There is a vaccine, but it has side effects.

Film — Live-Action

• Alien: The black liquid Chemical A0-3959X.91 – 15 featured in Prometheus and its direct sequel Alien: Covenant. It's described as a pathogen that infects viable hosts and produces hybridized predatory monsters like the Neomorphs, who themselves come out of spores that insert themselves into a host's body skin via Orifice Invasion. The pathogen was specifically designed by the Engineers to ultimately eradicate all fauna in a planet's biosphere while leaving the flora untouched. The Covenant novelization goes into greater detail, with David saying that Neomorphs — like the Xenomorphs — inherit traits and abilities based on their host species.
• Bite: Casey experiences a gruesome Slow Transformation into a human-insect Artificial Hybrid due to a bug bite, and she lays eggs which spawn more insects and escape. It's implied the spawned bugs will cause each human they bite to suffer the same fate as Casey.
• Black Sheep (2007): The Virus in this film is a mutagen originating from a mutant lamb fetus which spreads to other sheep via bites. Besides turning the sheep into ferocious flesh-eaters, the mutagen can cross to sheep-bitten humans, in which case it turns them into likewise-carnivorous were-sheep.
• The Blob (1958): The monster could either be this or Grey Goo. Nobody's gotten close enough to examine it without being digested.
• Contracted: The infection in the films is transmitted by fluids (e.g. saliva, semen or blood) and transforms people into zombies over the course of a few days.
• The Crazies (2010): The Trixie virus is a bio-weapon derived from the same family of viruses as rabies, which over the course of several days makes its infected hosts descend into homicidal mania and then makes them go from looking normal to gaining freaky eyes and wormy grey skin. The Trixie virus' infected victims can crudely mimc human behavior but it should become clear to any common-sensed person within 30 seconds that they're behaving off.
• Dawning of the Dead: The virus in this film is a millenia-old virus that was discovered in melting permafrost in Siberia. The government contracted Prof. Greg Laborde to research it, and learn how to use it to extend the lives of soldiers so they can continue fighting after death. The virus was stolen by anarchists and released in 40 heavy populated areas around the world, which caused the Zombie Apocalypse.
• Daybreakers plays with this in interesting ways. Humans bitten by vampires will turn into vampires, resulting in almost the entire population being turned by the time the film is set. However it turns out that drinking the blood of a vampire-turned-human is a cure. Near the end of the film, everyone is suffering from deprivation as a result of the dwindling human population, so several soldiers mindlessly feed on one of the former vamps. When they turn back, they're then fed on by their starving comrades who also turn back, rippling outward until there are a few survivors left in the room.
• Day of the Dead (2008): The Wildfire virus which creates the Flesh-Eating Zombies is apparently airborne, causing victims to at first develop flu-like symptoms, then zone out before turning, although bites can also infect people who the airborne strain doesn't get to. Fortunately, you're only a mortal threat to your loved ones if you ate meat — if you're a vegetarian, not only will you make a docile zombie, but you'll remember people you had a crush on (or at least, you'll remember having a crush on them) and even try and defend them from other zombies.
• Feral (2017): The feral disease will lay dormant in its host body until sundown. When that happens, the virus activates, turning its host into a vicious bloodthirsty savage.
• Howl (2015): While stories of becoming a werewolf upon being bitten by one are definitely not unheard of, this take on the trope plays it out more like a zombie outbreak, slowly causing an apparently permanent transformation and turning the humans into feral predators who'll eat their loved ones and former allies alive.
• I Am Alone: The virus, upon infecting its host, can zombify within 32 seconds to a minute. When Jacob was infected, it took him days to turn.
• Jennifer's Body: Needy finds out that being scratched and bitten by Jennifer rubbed some of her succubus powers off on her - without the disadvantages Jennifer was suffering from.
• The curse in the Ju-on franchise (and its American counterpart, The Grudge and its sequels) operates this way. Not only do those who are killed by the curse become ghosts in its service, but the death curse can even be spread by still-living people who have come into contact with it (an element which was removed from the first US film but reinstated for the sequels).
• The no-budget Japanese imitator of the above, Ju-Rei, also uses a curse that operates on the same principles, with the caveat that living people don't seem to be able to spread it the same way they do in Ju-on.
• The Matrix: Agent Smith in the sequels. After Neo tries to delete him, he comes back with the ability to copy himself into other people. It's ironic, given that he was disgusted by the human race and called them a virus in the first movie. Also, for symbolism points, his sunglasses change after his resurrection, going from square to slightly more rounded, with the general shape of a protein capsule of most viruses. Throughout the trilogy, all the Zionites and their supporters (Seraph, the Oracle) have round glasses while Agents and their sympathizers (Cypher) wear square ones — the fact that Smith's glasses are something in between furthers the symbolism and is another example of the series' Fridge Brilliance.
• In Pathogen, the zombie virus is a waterborne disease.
• [REC]: While the doctor character compares the outbreak to rabies and the tape to influenza, the climax suggests that the contagion has a supernatural origin. The second film confirms it: the virus is actually the vehicle of a worm-like demonic entity which uses it to control the infected and jump its mind from one to another. The American remake Quarantine (2008) picks up on the appropriateness of rabies as a real-life example by making a mutated version the threat, without any supernatural elements.
• Rise of the Planet of the Apes had a viral-based drug for Alzheimer, that when applied to apes made them smart on near-human levels. One new batch of the virus turns out to be fatal to humans, leading to much of the population being dead by Dawn of the Planet of the Apes. War for the Planet of the Apes has the virus mutate to something more like the trope: it instead makes humans mute, like the ones from the original movie, and is infectious to the slightest contact.
• The alien in Slither, which spreads through parasites that turn hosts into drones for the Hive Queen, controlled through a Hive Mind.
• In The Thing (1982), the titular creature is the literal embodiment of The Virus — a fiendish micro-organism that replaces the victim's cellular structure with itself. The Thing also displays the ability to perfectly mimic any living thing — until it's threatened, at which point it flips out and begins sprouting tentacles, giant toothy mouths, et cetera.
• As the name implies, the antagonist of Virus. A transmission from space takes control of a (seagoing) ship's computers and begins building something. When the heroes ask the program what it wants, it replies with a list of body parts.
• Virus Shark: The driving force of the movie is finding a cure for SHVID-1, an obvious Expy of COVID-19 that was discovered in sharks.

Folklore

• In Aboriginal Australian Myths, the Yara-ma-yha-who is a type of frog-like creature that turns humans into more of themselves by catching and repeatedly digesting them, spitting the victim (usually a child) out after a long and tortuous transformation.
• Vampires. It is a standard feature of their mythos that they turn others into vampires by biting them. Some modern variations, however, change it slightly so that one must drink the blood of a vampire to become one, thus getting around the conundrum of why there isn't a Vampire Apocalypse in such stories.
• Werewolves, in more modern versions, turn others into werewolves by slashing and biting.
• Zombies are complicated. Depending on the verse, it could be a bite, a chemical, a magic spell, or even nothing at all; the "classic" zombie of pre-Hollywood folklore is simply a corpse raised by a presumably evil magic-user of some stripe or other to do its master's bidding and lacks the raw ability to inflict its own condition on others. (It may still kill you, of course, but you're not going to get up again as a zombie yourself under your own power afterwards.)
• That most dreaded and contagious of schoolyard infections: Cooties!

Literature

• The Yeerks from Animorphs are a race of parasitic slugs who infest a host body by entering through the ear and wrapping themselves around its brain. It can then read the hosts mind and control the host's every action, imitating its behavior. The mind is left a prisoner, able to think freely but unable to control any aspect of their physical selves. They are returned to themselves briefly every three days, when the Yeerk needs to feed.
• In Neil Lee Thompsett's Becoming Human, humanity itself is this. Not a species, a disease.
• Bruce Coville's Book of... Aliens II: The fog in The Plant People slowly converts humans into plants.
• Vord in Codex Alera are a sort of gumbo version of this, combining several Virus tropes into one vicious nasty.
• In Cujo, the virus in question is rabies. A St. Bernard is bitten on the nose by an infected bat and turns into an insane killing machine in as little as a week from initial infection. There is some Artistic License – Biology involved here: rabies has an incubation period of around one to three months, and when Donna is bitten and infected later, she begins to show signs of primal rage from early onset; the violent tendencies shown in infected animals do not usually manifest in humans in the same way, and besides, while post-exposure treatment before symptoms is thankfully nearly 100% effective, after symptoms treatment effectiveness is radically reduced and survivors still usually have severe neurological problems for the rest of their lives.
• Dances of the Men by V. Pokrovsky has a new one, in case old bites and microbes were too easy to block. A scientist has invented a Super Serum-level brain stimulation via complex microwave pulses. When he tries this trick on humans, their brains re-emit the pulses, with the power growing until it can melt holes in wire veils at point-blank range, just before boiling itself. Not that it matters to that veil's owner much — the powers it still gives are deadlier anyway, and most of infectees in the final stage are violently insane.
• Eden Green follows the spread of an alien needle symbiote that renders its hosts immortal; the title character is on a mission to learn how to destroy it and prevent further infection.
• The Eschaton Series has mimes who reproduce themselves by hitting humans in the face with pies — the pies are full of nanotech that reformats the human into a new Mime, complete with more pies. Lucky for those being pursued by Mimes, they are afflicted with the sort of tics you'd expect, such as occasionally being trapped inside an invisible box or having to walk against the wind.
• In The Executioner and Her Way of Life, Machine Society's Pure Concept "Vessel" works this way. It attaches to people and slowly overwrites their bodies with the power of Pure Colors, eventually erasing their identities entirely and turning them into empty shells which become extensions of Machine Society.
• Faction Paradox has "Faction biodata", which can be injected into such things as regenerating Time Lords or pure life energy creatures melding with a planet's ecosystem, turning their hapless victim into a tool of the Faction via an extremely vicious form of Cosmic Retcon. This would normally be bad, but it becomes horrifically bad in Interference when the infected Time Lord is the Doctor.
• Glasshouse: Curious Yellow is a digital virus that is capable of controlling people and removing their memories (as well as computer records) of... something. What, no one ever found out, even after the long, brutal war to contain and defeat it.
• In Harry Potter, lycanthropy is a metaphor for AIDS, as far as many fans are concerned.
• InCryptid: Lycanthropy-w, the virus that creates werewolves, can infect any mammal (including mammalian cryptids), though it's immediately fatal in anything smaller than a dog, and ultimately fatal in all cases, since the body simply can't handle the stress of constant transformation. Treatment is possible if it's identified quickly enough.
• In The Iron Teeth, ghouls are monsters that spread through an infection. Bites and contact with their bodily fluids are the usual vectors.
• The eponymous viral contagion in William Bebb's KECK series is caused when a migrant worker working at a pharmaceutical company killed in an accident involving toxic waste, which then mutates in his body to become a biohazard that reanimates the dead and acts as a Hate Plague in living victims.
• In The Laundry Files, zombies are regular humans whose brains have been overwritten by a low-level demonic entity. The demon multiplies by touch; the briefest skin contact with a zombie turns you into a new one, and the cycle continues from there.
• Legacy of the Dragokin: Jihadain's monsters can transform their victim into the same kind of monster by biting them. In this way she create an army from muggles.
• The Flare from The Maze Runner is a Hate Plague that turns those infected into animalistic, raging zombies. It was originally released by world governments after the solar flares as a means of population control, but it mutated and spread uncontrollably...
• The Newsflesh universe has Kellis-Amberlee, an accidental Synthetic Plague created when "Kellis flu" (a genetically engineered virus meant to cure the common cold, which it does do) met "Marburg Amberlee" (a genetically engineered variant of the Marburg virus which was a successful effort to cure cancer) and the two combined into a new bug, which still has the same effects as its parents, but has the nasty side effect of turning any infected mammal (which quickly comes to mean "every mammal", since it's airborne) over 40 pounds into a reanimated zombie on death, and can spontaneously "amplify" in a living carrier of sufficient size, causing it to bypass death and go straight to chompy zombie.
• The Infection in An Outcast in Another World only affects animals, and horribly mutates them. The longer an animal has been affected, the worse the mutations get, to the point that they become borderline Animalistic Abominations.
• In Steven Hall's The Raw Shark Texts, Victorian "gentleman scientist" Mycroft Ward gradually becomes this. He cheats death by transferring his personality into a younger man, and this new body cheats it again by sharing knowledge with a second person. It all goes bad when the increased self-preservation instinct causes him to search out more and more hosts.
• The Conjoiners, a Hive Mind culture in the Revelation Space Series, are actually the good guys in a number of stories. They started out as a handful of scientists who linked their minds as an experiment and subsequently released a virus to assimilate more minds into the collective, but later their goal became simply to survive. They consider conscripting their enemies a more humane alternative to killing them.
• The Ring: In Spiral, any time a woman watches the cursed videotape (or any of its derivatives) whilst ovulating, they become pregnant with a clone of Sadako, which develops to birth in a week, leaving the host to die.
• Star Wars Legends:
  • In Death Troopers and Red Harvest, a virus is delivered through a chemical compound derived from a plant and other Sith formulas, which turns the victim into zombies. Not kidding, zombies in Star Wars. The virus is transmitted through bites or exposure to infected blood, and the horde even some kind of Hive Mind to boot.
  • Star Wars zombies are nothing new, though in their Galaxy of Fear appearance, they don't bite and aren't infectious. However, The Planet Plague does have Blob Monsters that creep about and, on skin contact with people, infect them with viruses that turn them into blob monsters.
  • One book also has a virus that turns its victims into metal zombies. It starts as a metallic tumor on the skin, then quickly spreads, changing living flesh into metal. It attacks the brain as well, effectively lobotomizing the victim.
• The Three Stigmata of Palmer Eldritch: The title character distributes an exceptionally trippy drug with the side effect of causing the users to think more like he does than they used to — and also causes them to spontaneously develop Palmer's "three stigmata", which are artificial eyes, a metal jaw, and a replacement arm.
• The villains of Ukiah Oregon are this. Oddly, so are the heroes. The alien Ontongard are an alien virus that infects anything living. Almost all hosts die, but the survivors become part of a Hive Mind, and become part of the Ontongard's purpose. The anti-heroic Pack propagate themselves the same way, but allow the victim to retain their own identity and personality.
• In Philip K. Dick's short story "Upon the Dull Earth", a weird necrophilic woman attempts a bizarre experiment to speak to the "angels" who supernaturally rule the Earth, which fails and claims her life. Her grieving boyfriend bargains with the angels to bring her back in a Deal with the Devil. Unfortunately, the angels screw up when doing so — the girl comes back, but only by hijacking another person's body, taking over her sister's body and physically transforming it into her own. The angels seem unable to stop this process, either — soon everyone in the world begins spontaneously transforming into a duplicate of the girl. Madness and horror ensue.
• In The Wheel of Time, 13 channelers weaving a particular kind of Black Magic through 13 Myrddraal can forcibly turn any other channeler to the Dark Side. The victims are described as having unnatural facial expressions, "like the smile on the lips of a corpse", and "something not-quite-alive inside those eyes. This didn't seem to be a man, but a parody of one. A shadow stuffed inside human skin."
• The hermaphroditic eponymous race in Wraeththu change young human men into Wraeththu by transfusing them with Wraeththu blood, then stabilize the transformation via sex.
• The Solanum virus from The Zombie Survival Guide and World War Z by Max Brooks is an attempt to codify the "rules" of zombie fiction as portrayed in the Romero films and similar works. Solanum is lethally toxic to all animal life if ingested, it kills and reanimates humans bitten or scratched by the infected or exposed to their bodily fluids, and it can potentiality reanimate infected people who die from other causes while the virus is incubating. However, it does not raise long-dead people from their graves.

Live-Action TV

• Random Virus in Ace Lightning: former Lightning Knight turned mentally unstable cyborg. Interesting in that his old self is still there — it's just that he can't help switching between them on a regular basis.
• The Yeerks from Animorphs. They are a race of parasitic slugs who infest a host body by entering through the ear and wrapping themselves around its brain. It can then read the hosts mind and control the host's every action, imitating its behavior. The mind is left a prisoner, able to think freely but unable to control any aspect of their physical selves. They are returned to themselves briefly every three days, when the Yeerk needs to feed.
• This is a key trait of Dezumzorya, the Big Bad of Bakuryuu Sentai Abaranger. It combines physical infection with More than Mind Control to great effect.
• Buffyverse:
  • Buffy vampires have their previous selves' souls replaced with a demon (though it can be retrieved later by a spell). This is a reversion to the original vampire legends in Eastern Europe, in which spirits called upir, which are supposed to be simple psychopomps (escorters of the dead to the afterlife), glom into the now-soulless bodies and walk about in search of fun. Despite not really being the same entity, the vampires retain their memories and usually end up being a twist on the original person's personality, particularly the repressed parts:
    Willow: It's horrible! That's me as a vampire? I'm so evil and... skanky. And I think I'm kinda gay.
    Buffy: Willow, just remember, a vampire's personality has nothing to do with the person it was.
    Angel: Well, actually... [sees Buffy's expression] ... That's a good point.
  • Angel's response reveals that the common explanation for vampirism doesn't quite work for all vampires. In Angel, when Angel's soul is again lost and the gang attempt to put it back, Angel has the chance to interact with his "alter ego" Angelus via a drug-induced dream state. Angelus puts it to Angel that they are simply two sides of the same person rather than literally being two distinct personalities, since Angel is perfectly capable of exactly the same kinds of vicious acts. "Angel" just regrets it afterward.
  • Werewolves are created when a person is bitten by another person and survives. The interesting bit is that werewolves don't have to be transformed when the bite occurs.
  • In the Buffy the Vampire Slayer episode "Bad Eggs", students participating in a health project raise eggs as if they were children. The eggs end up hatching and the demons inside of them take control of whoever was supposed to take care of them. All of the egg-demons are controlled by the "mother" demon below the school.
  • Jasmine from Season 4 of Angel turns everyone into her fanatical worshipers willing to kill others for trying to free them from her influence. Ironically, being infected with her blood frees you from her control. Jasmine refers to it as "spreading the hate".
• In the Community episode "Epidemiology", Greendale becomes the epicenter of the outbreak for an experimental virus designed by the army.
• Episode 5 of Danger 5 features a contagion that's turning the Allied soldiers into Those Wacky Nazis. Its source is a literal wellspring of the "Aryan seed", and it is sexually transmitted. Exposing it to Swiss blood is the antidote, since in the Dangerverse, Swiss blood is... made of gold.
• Doctor Who:
  • The Cybermen seek to "upgrade" the universe by turning everyone into versions of themselves.
  • "Mission to the Unknown" has the Vaarga Plants. A single touch from them slowly and painfully turns a person into another Vaarga Plant, and even killing the afflicted doesn't stop the transformation. Daleks keep them as guard dogs.
  • "Inferno": The Primords. If they even touch you — hell, if you touch that green stuff for even a fraction of a second — it's only a matter of time before you become a mindless Primord.
  • "The Invisible Enemy": The Nucleus is a literal virus that's taking over human beings, aiming to take over the entire universe; in the final episode, it gets enlarged and is... a giant prawn.
  • "The Empty Child"/"The Doctor Dances": The titular Child is a little boy raised from the dead by alien medical nanomachines that have no clue how to rebuild humans. Any time he touches someone, the nanomachines reprogram them to the way they think all humans should be — down to the gasmask and injuries the boy had when they found him.
  • "New Earth": The diseased clones try to get others sick, although it's not clear that a "second-generation" infectee would do the same.
  • "42": A temperature-raising infection spreads among the crew of a cargo ship falling into a star. They're actually being possessed by the star.
  • "The Waters of Mars": The Flood, literally a (water-borne) virus. An unusual one, as it can exist and be dangerous outside of a host as well. It's harder to avoid and does its work faster than most of the examples on this page.
  • "The Time of Angels"/"Flesh and Stone" adds something like this to the abilities of the Weeping Angels. "That which holds the image of an Angel becomes itself an Angel."
  • "The Vampires of Venice" naturally has vampires. They're actually fish-like aliens who are converting humans into members of their species by injecting them with their blood.
  • "Night Terrors" combines this with Creepy Doll. The people trapped inside the dollhouse are chased by creepy peg dolls who will turn the people into more of them if they catch them.
  • Praxeus is an alien disease with the ability to hijack other lifeforms, spread through ingesting plastic or injuries the infected cause to the healthy. Suki also indicates that it's aware of any attempt to cure it and will take steps to sabotage cures through its hosts.
• Game of Thrones: People killed or touched by the White Walkers or their wights become wights in turn. The Night King, the leader of the White Walkers, can also turn human infants into White Walkers.
• In Helix, two strains of Synthetic Plague have jumped from lab animals to humans during a viral outbreak. Unlike NARVIK-A, which causes hemorrhagic shock and eventually liquefies its victims, NARVIK-B, the mutated strain, does not kill its victims, but instead modifies their behavior so they become super-strong, paranoid, aggressive and biologically driven to infect others via forcible transmission, which entails assaulting and restraining victims and vomiting a black secretion into their mouths.
• In Let the Right One In, vampirism is explicitly the result of a virus that any person who's bitten will become infected by (assuming that they survive).
• In Lexx, the Big Bad of Season 2 is Mantrid, a Mad Scientist in a robotic body who creates an army of flying robotic arms that convert other living beings into more flying robotic arms. Eventually, every living thing in the Light Universe except for the Lexx and its crew is converted into Mantrid's army. Not just every living thing. Every thing. Including the stars.
• "The Sickness" from Lost is almost certainly this. For five seasons, it's suggested that the Sickness is just the delusion of a madwoman... until season 6, when Claire and Sayid become infected, start following the orders of the Big Bad and kill a whole bunch of people.
• The Outpost features this as a major threat in Season 3. The season's Big Bad, Priestess Yavalla, comes into possession of the white kinj, which can self-replicate and pass the offspring kinj into other people via physical contact, linking them into a Hive Mind (known as the United) dominated by the original host. This is treated very much like a plague outbreak by the non-United, including referring to the United as "infected" and turning the outpost into a quarantine zone to try and keep the United out.
• In Power Rangers in Space, there is the Barillian Bug, an insect-like Monster of the Week created by Darkonda with a sting that can turn people into monsters like itself who have the same sting. Darkonda intends to use it this way, but it only infects Carlos and Cassie before an antidote is found and the actual Bug is destroyed.
• The Festering Fungus from Primeval takes root in human skin, eventually taking over the brain and transforming the host into a bizarre killer fungus creature.
• Epideme from Red Dwarf is an intelligent artificial virus designed to block nicotine cravings. Unfortunately, he decided he'd rather spend his time stealing his various hosts' knowledge before killing them by starving their bodies of nutrients and oxygen, then hijacking their bodies, each time forcing them to bite someone else and transfer him to a new host.
• Stargate Atlantis: Inverted when the good guys invent a virus that turns enemy Wraith into docile, submissive humans. Then there's the Hoffan retrovirus, which makes the host lethal to Wraith attempting to feed on him/her. Problem is, half of the hosts are killed off by the virus itself after a few hours.
• Star Trek:
  • "We are Borg. You Will Be Assimilated. Resistance is futile." In some shows they inject "nanoprobes" into their victims (which rewrite the victim's DNA and cause them to grow Borg implants), and in others it's a more involved process that includes surgery. In Star Trek: First Contact, the Borg use both nanoprobes to convert Enterprise crew into Borg drones and surgery to graft tools and scanners to the drone body. The Borg's "assimilation tubules", which introduced nanoprobes into the series and made the Borg more this trope, appeared for the first time in Star Trek: First Contact, suggesting in-universe that they had assimilated this technology from one of their conquered species.
  • In the Star Trek: The Next Generation episode "Aquiel", the Enterprise-D encounters a "coalescent organism" which kills someone and then replaces them. By the time they realize it, Geordi nearly becomes its next victim.
• Supernatural: The Croatoan Virus is a demon-made virus which in its premiere makes people Ax-Crazy, but in later episodes outright turns them into mindless Technically Living Zombies. This trope is also Played Straight in Season 6 by vampires and Jefferson Starships, when the Monster Progenitors direct them to start turning as many humans as possible into their own kind with the aim of cutting off the flow of souls to Hell.
• Teen Wolf: Seems to be the case with lycanthropy, but mainly to those who have been turned and never wanted to be a werewolf to begin with. Some people, like Derek and other members of the Hale family, are naturally born with it.

Tabletop Games

• Dungeons & Dragons has the olive slime, yellow musk creeper, and other monsters of this kind:
  • One prominent example is the vargouille; it's a relatively low-level monster (Challenge Rating 2) that reproduces by "kissing" members of another species. Unless this kiss is cured with an appropriate spell, over twenty-four hours, the victim's hair falls out, their head becomes more wrinkly, the ears grow and become wings, and eventually, the head separates from the body and becomes another vargouille. It was even more creepy in the first edition, when the separated head would still have a variety of internal organs attached, dangling down from the neck.
  • A chaos beast can turn mortals into other chaos beasts.
  • Blue slaadi transmit a magical disease known as chaos phage through their bites and their claws, which unless shaken off will cause infectees to transform into red slaadi or, if they're spellcasters, green slaadi. Red slaadi themselves inject slaad eggs through their claws, which hatch into diminutive larvae that grow within the victim and eventually eat their way out, emerging as new blue slaadi.
  • Many undead have the power to turn anyone they kill or Level Drain to death into an undead of the same kind under the control of their killer.
  • Mind Seed is one of the most insidious psionic powers in 3.5. Implant someone with a Mind Seed and it will slowly reshape the victim's mind — against their will or even without them noticing — into a mental replica of the psion at the time the power was used. Though the resulting personality will still have their own free will, it will still share all the goals and priorities of the original psion.
  • Kaorti reproduce by infecting humans, elves and the like, causing them to transform into more kaorti. Those who are cured of the infection before transformation becomes irrevocable have dreams about the Eldritch Abomination that created the kaorti from human or elf mages in the first place.
  • Averted by zombies, which are non-contagious corpses animated by spells.
  • Elder Evils, a sourcebook on all things Cosmic Horror Story, gives this power to the Sealed Evil in a Can Father Lymic, with the Brood created by him given a fraction of his Elemental Powers over ice. His goal is to ultimately corrupt the world, turning it into a Single-Biome Planet of snow and darkness.
• The Exsurgent virus family in Eclipse Phase. Different strains can infect computers... or flesh...and the result is never, ever pretty, usually featuring Body Horror and always featuring Mind Rape. Oh, and they're very, very adaptive. Like, normal-viruses-on-crack adaptive. A digital strain can infect a nanofabricator, reprogramming it to produce biological and nanotechnological variants, which then go on to infect other beings and devices. Oh, and it can also be transmitted as pure sensory information, so you can get infected just by watching the wrong video, known as a basilisk hack.
  "What's worse to contemplate, though, is that we may get another major outbreak that spreads to multiple habitats before we can contain it. That might get very, very bad, very, very quickly."
• One of Feng Shui's many Creature Powers is "Corruption", which allows a supernatural creature to infect others with their supernatural essence, and in this way create more of their kind. Corpse factories in the Glimpse of the Abyss supplement use a variant of this to create zombies for all your Zombie Apocalypse needs.
• GURPS:
  • Riders (from GURPS Aliens) and Valkryies (from GURPS Traveller: Alien Races 4. Note that these are both ostensibly science-fiction (rather than fantasy or magical) species.
  • 4th Ed. GURPS Ultra-Tech has a metamorphosis virus that can be weaponized into either this or a version that turns everyone into random things, which can be much worse.
  • Another electronic example is The Virus in Traveller: The New Era, originally designed as a weapon for shutting down the navigation systems of enemy warships in order to end the war without further bloodshed. Unfortunately the version that was prematurely unleashed when the research station working on it was attacked would shut down every computer in the vicinity through means unexplained (though heavily implied to be psionic in nature), with... interesting consequences if that computer happened to control (for instance) a nuclear reactor or a life-support system. Then it evolved full intelligence, which didn't improve matters.
• Magic: The Gathering:
  • Phyrexia, in all its incarnations, has this as one of its most prominent themes. Several New Phyrexian cards are older cards given a Phyrexian twist.
  • A legendary creature card from the Innistrad set, Olivia Voldaren, is a classic infectious vampire: one of her abilities deals a point of damage to a creature and turns it into a vampire, and her other ability allows her controller to take control of any vampire as long as she remains in play.
• The short-lived horror RPG Nightlife had a race of borg-like monsters that embodied The Virus trope. Surprise, surprise, they were called "the Virus".
• Nobilis: Actuals that are drawn out of the spirit world tend to occupy people or things to this kind of effect. One sample Actual, the Family, consists of an entire clan of elegant, long-haired and innocent people with eyes the colour of pale quartz, who take in people in need and help them, only for those people to eventually transform into more members of the Family.
• One Night Ultimate Werewolf:
  • The Alpha Wolf (introduced in One Night Ultimate Werewolf Daybreak) can replace a villager's card with that of another werewolf card, bringing that player to the werewolf team.
  • The vampire team from One Night Ultimate Vampire can choose a non-vampire player to receive the Mark of the Vampire which converts the player to the vampire team.
• A third-party Pathfinder supplement inverts this with the Obitu race, a race of living skeletons created by a virus that only infects the undead.
• Rocket Age: Although it hasn't yet been used in a printed adventure, the game does provide GMs with the Infection trait, allowing them to make their own space zombies and vampires.
• Shadowrun: HMHVV (Human-Meta-Human-Vampiric-Virus), a supernatural disease that afflicts sapient primates — meaning metahumans and sasquatches — with lycanthropy and vampirism. There are three known strains, where strains II and III (the lycanthropic and ghoul variants) infect by any exchange of bodily fluids (i.e., being bitten or scratched) while strain I (the vampiric variant) only infects people completely drained of Essence. Dark Terrors implies that HMHVV is actually a meta-sentient force. Further, if the Infected commit sustained cannibalism, the virus concentrates to the point that it manifests eldritch gods.
• Warhammer 40,000
  • Powers of Chaos, which can quite effectively turn the open mind into a willing cultist and a traitor to mankind.
  • Tyranid swarms, the insidious Genestealer cults, the insidious Tau propagandists/brainwashers, the insidious Necron Pariah harvest, etc., etc., etc. Rarely is any given conflict zone not subject to some form of The Virus. Let's just say that in this universe, General Ripper types typically have the right idea.
  • The dreaded Obliterator virus turns you into something truly horrific. The first tip that something horrible is going on is when you realise that you're spontaneously generating ammunition for your gun, which is becoming gradually more attached to your hand. From here, it's only a short trip to the point where you're an out-and-out psycho who can absorb guns, then create them again fused to your flesh. When compared to the fates of some Chaos cultists, especially those who fail (think living flesh bag of pain and get worse), the bloodthirsty insanity and difficulty of speech is not that bad and the Body Horror comparatively mild. Once transformed, you're likely to see your fate as Cursed with Awesome.
  • The jungles of Catachan has a cactus-like plant called the Spiker which fires its spikes out at nearby animals. These spikes contain mutagenic chemicals that transform any animal unfortunate enough to be pierced into another Spiker.

Theatre

• The opera Help, Help, The Globolinks! has invading aliens called Globolinks whose only known weakness is music. Humans touched by Globolinks are gradually transformed into Globolinks, first losing the ability to speak human language.
• In Eugene Ionesco's absurdist play Rhinoceros, the townsfolk are all spontaneously transforming into rhinos.

Toys

• The Makuta's virus and the Dreaming plague in BIONICLE, although it's ambiguous as to whether the latter was actually transmitted virally or not.

Video Games

• The plot of Abuse revolves around a mutagen of the same name created from the gene that causes violence and aggression in humans, which mutates them into grotesque Xenomorph-like creatures.
• Area 51 revolves around an alien virus being unleashed and causing a Zombie Apocalypse in the area. The Game Over screen shows a video of the protagonist morphing into one of the alien mutants.
• The virus blocks in AstroPop. They can't be grabbed, and you can only get rid of them by making a match next to them. They also "infect" other blocks, turning them into more virus blocks. You can interrupt the transformation if you grab the block before it's transformed.
• Bloons Tower Defense 5 has Viral Frost, one of the tower upgrades of the Ice Monkey. When Bloons are frozen by Ice Monkeys with this upgrade, other Bloons that touch these Bloons will also be frozen, as if the freezing effect is spreading like a virus, hence the name.
• Borderlands 2's "Commander Lilith and the Fight for Sanctuary" DLC features Paradise Gas, which turns anything that breathes it in into a mindless monster plant zombie.
• Crysis 2 has a viral outbreak in Manhattan that may or may not be from the Ceph, and certainly wasn't mentioned at all in the original Crysis. A group called C.E.L.L. apparently is tasked with containing it at any cost... including the murder of any potential carriers.
• Kuru is a real disease that stems from cannibalism, and can invoke a zombie like state. Kuru mutating to Hell on Earth proportions is the basis for Dead Island.
• The Dead Linger takes place after a virus called HNZ turned the majority of people into zombies suffering from necrosis, reduced intelligence and a hunger for human flesh. The only good thing is that they become slower and eventually die off if they "live" long enough. The really bad thing: The player is not immune!
• The Dead Rising series has an example that isn't, strictly, a virus: Ampulex Compressa Giganteus are genetically modified wasps created to address a food crisis, but mutated so that its parasitic breeding practices which originally only impacted butterflies affected humans, leading to infected humans becoming zombies.
• Dead Space's Necromorphs are unique in that only one of its forms is The Virus and it can only infect dead people. It's the task of the other Necromorphs to ensure there are dead bodies to infect. The Virus can somewhat infected people but only after weeks of being in contact with the source or at least being around the marker, drive them insane and kill themselves, after a few more hours the virus takes effect. The infector version just speeds up the progess from 10 hours to 10 seconds.
• For a technological example: the unnamed computer super-virus from Descent, which takes over mining robots and turns them against humans, while at the same time drastically increasing their AI. It's much more powerful in the novel adaptations, in which the virus can take over just about any machine and give it sentience, and possesses AI of its own, allowing it to intelligently react to and avoid anti-virus measures.
• Averted in Digital Devil Saga, where the Demon Virus is not communicable. The only way to be infected with it is to be exposed to a certain piece of data; it's a computer virus.
• The A-Virus in Disgaea 4: A Promise Unforgotten is a humorous take on the trope, but nonetheless horrifying in its own way. It transforms the infected into Axel, in both body (Clothes included, somehow) and mind, Initial signs of infection include random bouts of hotbloodedness, and/or referring to oneself as "ore-sama" (Not to be retained in the English version for obvious reasons). Everyone gets better in the end, though. Or not.
• The Darkspawn taint in the Dragon Age series. The Darkspawn spread this disease wherever they go, turning any living things that are exposed to it into horrible monsters. Yes, this includes people. The taint unites the Darkspawn in a primitive Hive Mind, though only an Archdemon, a draconic Old God corrupted by the Darkspawn taint, can unite all of the Darkspawn hordes. That's right, this particular Virus can corrupt gods.
• Dragon's Dogma II has the Dragonsplague, a disease that only affects Pawns, but is highly contagious among them. It originates from contact with draconic enemies, and spreads via proximity with other Pawns. Symptoms include a sanguine glow from the eyes, surge in strength, headaches, lethargy, and disobedience. In its terminal stage, Dragonsplague causes the infected Pawn to transform into a dragon, going on a rampage in whatever town or city you are resting at the time and completely depopulating it before returning to the Rift. Unfortunately, the only known way to cure Dragonsplague is for the infected Pawn to die and be sent back to the Rift.
• The Elder Scrolls:
  • Throughout the series, Vampirism and Lycanthropy are actually diseases (though divine in origin) which can be spread via any wound inflicted by a carrier of the disease. In the case of vampirism, it starts off fairly innocuous (fatigue, insomnia, nightmares) and is easily cured within the first few days of being contracted. Porphyric Hemophilia, Sanguinare Vampiris, and Noxiphilic Sanguivoria are a few of the disease that develop into full-blown Vampirism. Lycanthropy functions similarly, although in some cases, consuming the blood of a lycanthrope can cause the disease to immediately take effect.
  • Morrowind has the Corprus Disease (which will either turn you into an Eldritch Abomination or a Body Horror Technically-Living Zombie depending on the will of its creator) and the Blight (which kills plants, drives animals insane, causes health problems in humanoids, and can carry Corprus). In addition, there are some more mundane illnesses ("Swamp Fever," "Jitters," et cetera) that can be contracted as well, but they are simpler to cure.
• Emperor: Battle for Dune. The Contaminators, mutants spawned from Tleilaxu Flesh Vats. They carry a lethal virus capable of turning humans into additional Contaminators. There's also the non-human variant called the Tleilaxu Leeches, biogenetic tanks that create replicas of themselves by implanting larva in enemy vehicles, which damages the host vehicle until it's destroyed before hatching into another Leech.
• Extermination (2001) revolves around this. The Virus mutates and corrupts pretty much anything to do with water. The player will probably freak out about the time a puddle of water actually attacks/infects the player character. Getting 100% Infection and not curing it fast leads to a Non-Standard Game Over where the player watches the transformation into a monster.
• Fallen Legion Revenants features the Miasma. While it started as a slow acting, terminal respiratory infection, it eventually went From Bad to Worse causing humans to turn into zombies and animals into various monsters.
• Fallout:
  • The Super Mutants were created by the Forced Evolutionary Virus; the first game culminated in the player destroying the transformation vats, although they could agree to be turned into a Super Mutant to achieve a Non-Standard Game Over.
  • The plot of the Fallout 3 expansion pack The Pitt centers around the Troglodyte Degeneration Contagion. Most victims only suffer skin lesions, but the more severely affected lose their minds and become Wildmen, or worse, fully degenerate into Trogs. Nearly all children born in infested area become Trogs within a few weeks of birth, with the exception of Marie Ashur, the daughter of the slavers' leader, who has an immunity to TDC, offering hope for an eventual cure.
  • Vault 22 in Fallout: New Vegas is infected by a parasitic fungus that mutates exposed humans into Spore Carriers, which spread the fungus further; some of the fungus has escaped as far as Zion Canyon.
• Final Fantasy VII had the Jenova cells.
  • They started up a fairly innocuous power-boost, except in a few very specially treated individuals, who began to suffer from mad wanderlust and lose their minds. They then attempt to join up with the head of Jenova. The main character, who was traveling all over the world for a reason he could hardly justify, based on little more than instinct, and seemed to suffer occasional but horrific mental episodes, turned out to be one himself.
  • According to Ifalna, in her interviews with Professor Gast, Jenova first landed on the Planet and began spreading its cells like a virus, mutating the Cetra into horrible monsters under its control. The monsters employed the same abilities as mommy, able to absorb the appearance and memories of their hosts, and quickly slaughtered a whole civilization by imitating their loved ones. It seems that Jenova itself is an entity that travels from Planet to Planet, infecting the native inhabitants and transforming them into carriers to further spread its infection around, before bringing them all back and "reuniting" itself to travel to another Planet and continue the cycle. How long it's been doing this is anyone's guess.
• Final Fantasy XIV: Endwalker has the Blasphemies, Eldritch Abominations born from a particularly powerful entity's "song" that utilizes "Dynamis", the power of emotions, to warp mortals into monstrous personifications of despair. These creatures, in turn, cause others to fall into despair and transform into Blasphemies.
• Bacterion, Gofer, and Zelos of the Gradius series are incarnations of The Virus; Every time you defeat any one of these guys, the Bacterian cells that they are composed of will increase in numbers. Dr. Venom also applies to this too, since he's been modified by the Bacterians.
• The Flood in the Halo franchise, which latches onto sentient life forms, hijacks their body, mutates them horribly, and, when the host is no longer usable, uses it to incubate more Flood infection forms. The infection forms even look like macroscopic bacteriophages. That's not even considering how the Flood will also spread itself via airborne spores produced from Alien Kudzu and Meat Moss, or by directly attacking living creatures to intentionally infest their wounds with Flood biomass that spreads and infects the victim. When the Flood hijack enough bodies, they build a Gravemind; a giant, rhyming, Magnificent Bastard Hive Mind. To make it even worse, the minds and memories of every infectee are all assimilated into the Gravemind (it occasionally brags about transhumanism and ending suffering). This allows the Flood to, after a certain stage of outbreak, use any tool you can, if they can get their grubby tentacles onto it. Coupled with icky Body Horror and the assimilation and hacking of even spaceships, this Nightmare Fuel isn't too much of a stretch to imagine wiping out an entire pan-galactic civilization... which they are very heavily implied to have done before they arrived in the Milky Way galaxy and encountered the Forerunners. The Forerunner Saga reveals that they're actually the malevolent remains of a highly advanced species known only as "the Precursors", with those "remains" taking the form of a seemingly inert dust which contained DNA traces that would bind to any living creature it was exposed to and slowly mutate them and their descendants over the course of generations with increasing erratic and horrific bodily and behavioral patterns. During their conflict against the Forerunners, they literally crushed entire planets with Precursor technology and could corrupt AIs and Forerunners by breaking them through a form of argument known as a "logic plague".
• The Infection from Hollow Knight is a mix between Body Horror and Mind Rape. Any somewhat sentient creature can be infected by it, as it invades their dreams and takes hold of their minds. As it does, they are reduced to mindless creatures that attack anything in sight, their bodies start producing a sickly orange pus-like substance that makes their eyes glow orange, and if they've been infected for a while, starts to warp their bodies as they become covered in bright orange blisters and boils. The source of this infection is The Radiance, a goddess who tried to usurp the Pale King as the ruler of Hallownest, and was subsequently trapped inside the mind (or lack thereof) of the Hollow Knight. However, the Hollow Knight wasn't as mindless as the Pale King thought, and thus the Radiance's influence leaked out into the world in the form of the Infection, which ended up destroying Hallownest.
• Homeworld:
  • The Beast subversion entity from Cataclysm certainly counts. It quite literally rips its host apart, extracts their neurons, and then sets about using them to form an organic computer network it can subsequently use to control the ship they were flying, and hence infect more vessels. The quote formerly at the top of the page comes from the initial cut-sequence describing the entity — spoken by a poor engineer who sounds like he either wants to throw up or cry just about all the way through.
  • Ordinary Beast entities have an animalistic behavior and only care about multiplying. The original entity inside the Naggarok, however, is very much sentient: when the Imperialist Taiidan make first contact with it, the entity offers them half the galaxy if they repair the Naggarok's drives. It also tricks them into believing that the Bentusi are gone and that they will get the Nomad Moon. When the Moon is infected and is subsequently destroyed by the Somtaaw who in turn receive aid from a Bentusi ship, the Imperials flip out and turn against the Beast; cue the Naggarok calling in all of its "children" to catch the ''Kuun-Lan'' from three sides.
• The Jackbox Party Pack: In "Monster Seeking Monster", several of the monsters have a mechanic that involves spreading some kind of "infection" to players they date.
  • The Werewolf gets an extra heart if they get a date on the night of a full moon, but will lose half a heart if they get rejected during a full moon. Anyone they date during a full moon becomes a werewolf as well, gaining the advantages and drawbacks of dating on a full moon on top of their normal monster powers.
  • The Vampire turns everyone they date into a vampire, and those turned can subsequently turn others. At the end of the game, the original Vampire gets half a heart for every player that's been turned into a vampire.
  • The Mummy works like the vampire by spreading their "curse" to players they date, except they steal half a heart from cursed players at the end of the game. However, the curse is broken and the bonus is lost if the curse is spread to ALL the other players.
  • Anyone dated by the Zombie gets turned into a zombie after the next night, and they can infect others as well. If all the other players get infected by the end of the game, it triggers a Zombie Apocalypse and the Zombie wins regardless of how many hearts they had.
• In the Kingdom Hearts series, The Heartless consume the hearts of their victims and turn them into Heartless as well. However, there is a way to bring back the victim if their transformation happened to spawn a Nobody as well (which only happens if they had a strong heart), as slaying both their Heartless and Nobody will reform the original person. In later games in the series, this is represented by showing the Player Character's heart floating above their dead body on the Game Over screen if it was a Heartless that finished them off.^note In the first and second games, the heart is always shown regardless of what killed the Player Character, while Kingdom Hearts: 358/2 Days doesn't show shows the heart even if killed by a Heartless, which makes sense because the Player Character of that game, Roxas, is a Nobody and therefore does not have a heart for them to consume.
• The Last of Us has cordyceps, a real-world fungus that commonly infects insects, but which in the game has mutated to infect humans as well. Those infected with the mutated strain of cordyceps become zombie-like madmen who lash out at other people, with long-term infection causing progressively worsening Body Horror as the fungus breaches the body of the infected. Bites are a common form of transmission, but people can also contract the fungus by breathing in the spores released from the corpses of the infected.
• Left 4 Dead with the infection. In most cases the virus will turn most people into unintelligent "runner" zombies who will psychotically attack any uninfected individual. Body Horror comes into play when some of the infected mutate into special infected that feature warped bodies optimized for specific special abilities. The virus spreads by the infected transmitting bodily fluids (i.e., Getting bitten or being exposed to zombie bodily fluid), but it can also be spread by unknown means by asymptomatic carriers, individuals who show no signs of the infection but can still spread it. As it turns out, all eight Player Characters are carriers.
• Mass Effect has the Thorian, which is a plant-like entity that uses spores to mentally control people through pain. Also, there's Sovereign, a Reaper which controls the minds of its victims through a process known as "indoctrination". People controlled by Sovereign can only be saved by killing them. To further fit this trope, unguided or faulty indoctrination seems to wake the desire to become a cyberzombie, leading the victims to jump onto the zombiefying devices. This may or may not be intended as a failsafe. Both cases also involve instances where people choose to overcome the mind-control the only way they can.
• Mega Man:
  • Though it involves no physical changes aside from a possible palette swap, the Maverick/Sigma Virus from the Mega Man X series otherwise qualifies. Around X2, Sigma has become one with the virus, allowing him to get brought back between games for a reappearance and making virus victims extensions of Sigma's will to an extent.
  • The Maverick Virus was made by Wily himself, with his other creation Zero used as the Patient Zero. Before the events of the X series, Sigma fought Zero and the latter lost the virus, but Sigma got infected. This left Zero with some side effects in, like getting a power boost from the Sigma Virus and being mostly impervious to reinfection.
    • The Sigma Virus is shown in X5 to have two other varieties: the Colony Virus, planted onto the falling space colony Eurasia, and the Zero Virus, a crossbreed of sorts between the Colony and Sigma viruses, that shows up as purple holograms of Zero in Cyberspace. The fact that it can hurt Zero alludes to the possibility of Zero getting infected and becoming Awakened Zero if Eurasia is not destroyed, as well as implying that it might be based on the original, unmutated virus.
    • After the Maverick Virus, Mega Man ZX has Model W gaining the ability to manipulate the thoughts of humans and Reploids alike. This becomes important for Albert's Evil Plan.
    • The Roboenza in Mega Man 10 is essentially a robotic equivalent of the flu, except for the fact that it causes infected robots to go berserk. It was made by Dr. Wily of course, despite his claims to the contrary.
  • The "Zero Virus" in Mega Man Network Transmission is a newly spawned virus that began spreading after the events of Mega Man Battle Network 1 and has been adversely aflicting NetNavis infected with it, and what's worse is that there is a vaccine dealer going around the cyberworld selling fake vaccines that is causing the user's NetNavis to turn against them and go on a rampage on the net. A Mega Man X-savvy player can spot what is the cause of said virus.
• Metroid:
  • The Metroid Prime Trilogy's Phazon is an example, but to very varying degrees, depending on the game and target. In Metroid Prime 2: Echoes, the Ing also have a tendency to take over the bodies of other creatures, both living and dead.
  • The X Parasites from Metroid Fusion are a more traditional version of this trope, as their only purpose is to infect more people.
• Played with in Monster Hunter 4 Ultimate. The Frenzy Virus got its name from observations about its nature, but that's actually a misnomer. While it is communicable, it's not a pathogen. It's actually caused by the dust and scales Gore Magala spreads to give itself vision. Frenzied monsters just spread the dander they were contaminated with. Any "infection" would quickly burn itself out, were Gore Magala not an ill-tempered and highly mobile carnivore constantly causing new outbreaks.
• Mortal Kombat 1 reimagines the Tarkatans (a race of excessively fanged barbarians with arm blades) as Outworlders suffering from a disease called Tarkat. It mutates them into the series' iconic Tarkatan form, arm blades included, and gradually degenerates the afflicted's mental state until they become blood-crazed savages. While it is unclear how the disease is transmitted, Baraka's physical appearance alone gives a good example of just what damage it can do to anyone who contracts it. Mileena spends most of the game's story affected with its early stages so she retains a pretty outward apperance, apart from her mouth at times turning to its series-iconic monster maw. Those caught afflicted the disease are stripped of any titles and honors kicked out of Outworld society and forced to live in squalid colonies to avoid spreading the infection all over Outworld. There is a serum that can temporarily stop Tarkat's manifestation but no outright cure for it exists, hence Baraka considering death the only release he and his fellow infectees can hope for. Part of their stories is how Tarkat has affected their lives; Baraka was once a famed merchant and tribune before he contracted Tarkat and lost everything, and a large part of Mileena's story is her and her family trying to avoid letting the Outworld public become aware of Mileena's infection, with her inheritance of Outworld's throne hanging in the balance.
• Nobody Saves the World: Weaponized by The Zombie's "Zombite" skill which inflicts the "Infected" status effect on enemies. If an infected enemy dies, they spawn a generic zombie minion. These zombies can also inflict the Infected status effect with their basic attack, so in a crowded gauntlet of enemies, it's a viable strategy to just start a miniature Zombie Apocalypse.
• Overlord has an example of the "turns the victim into a mindless shambling zombie" type. The interesting part is how it spreads: tracing it to the source in Haven's Peak will reveal patient zero to be a Succubus Queen. The plague's a staggeringly virulent STD.
• The Tuurngait virus in the Penumbra series: Able to infect pretty much everything. Causes the infected to become stronger and more resilient or just ridiculously huge, depending on species. The virus is also sentient and controls all of the infected through telepathy. Oh, and it is older than humanity.
• In Phantasy Star Online 2, there's the Darkers/Falspawn, Eldritch Abomination creatures who spread their influence across the galaxy. While conventional weaponry can kill a body, only Photons can eradicate a creature for good, which is what ARKS is for.
• The Spore-shroom from Plants vs. Zombies 2: It's About Time is a rare heroic version. Any zombie killed by its projectiles turns into another Spore-Shroom on the square it was killed.
• Pokémon
  • One of the glitch Pokémon is Charizard 'M. Charizard 'M can also change all of a player's party Pokémon into Charizard 'M, but the moves and type do not change, and putting these "transformed" Pokémon into a box makes the other Pokémon Charizard 'M also.
  • Theres's a gameplay mechanic called the "Pokérus", which your Pokémon can pick up randomly during the game. This isn't a bad thing by any means because it helps your Pokémon get stronger stat boosts when they level up. They stop spreading it after a few days. Any Pokémon that's ever had the virus will retain the speedy growth forever. It also "freezes" when the Pokémon's in a box, allowing you to keep a few virus-spreaders handy for when you need to infect more of your mons.
  • Yamask and Cofagrigus's ability, Mummy, is this. When it is touched by the opponent their ability turns to Mummy. Potentially, this can cause a lot of Pokémon to be "infected". However, this is temporary, and wears off when the Pokémon returns to its Poké Ball.
  • Palossand's Pokédex entry implies this is how the species multiplies: its pre-evolution Sandygast spawns from the greed and hatred of the hapless Pokémon devoured by Palossand.
• The Sands of Time in Prince of Persia work like this. Once released, they instantly turn everything they come in contact with into a crazed Enemy to All Living Things (living in this case being the few lucky souls who weren't instantly transformed). Somehow, when the Prince is exposed in Prince of Persia: The Two Thrones, he manages to resist instant transformation, although he still gains a Superpowered Evil Side. The Corrupted from Prince of Persia (2008) are an aversion — it's their own damnn fault they're Eldritch Abominations now.
• Project Zomboid has the Knox Infection, the mysterious contagion responsible for the Zombie Apocalypse. The infection is spread through bodily fluid contact. In-game, players can contract the disease through injuries sustained from zombie attacks, but infection is not shown as a status ailment in the same way as a cold or infected wound: players will need to monitor their health after sustaining injuries from fighting a zombie, and take appropriate action as the situation dictates.^note Scratches have a 7% chance of spreading the infection, while lacerations have a 25% chance. Bites, on the other hand, are 100% guaranteed to spread the disease.
• [PROTOTYPE]:
  • The character Alex Mercer is The Virus. Under the right circumstances, The Virus gives a human being the powers to fly around and kill stuff with viral blades and whips and shit (as in the case of the main character); otherwise, you'll turn into a mindless, shambling, living zombie or a mutant with augmented speed and strength (as in the case of a lot of New Yorkers). It also infests warehouses (and ONLY warehouses for some obscure reason) to produce beefed up mutants that are incredibly annoying.
  • The Big Bad Elizabeth Greene is the other virus, and because of her aggressive nature and the fact that Mercer's virus seems inert (read: non-transferable) in him after the initial infection at Penn Station, she's more dangerous anyway. Alex can't get half the body count she does unless the player's doing it on purpose. The viral Alex, anyway.
• The strange virus from Puzzlebox boosts a person's resilience to injury, inspires creativity and drives its hosts mad.
• Rayman 3: Hoodlum Havoc: Andre, the black lum turns red lums into black lums and orders them about. It can be reversed however by making a black lum laugh, turning it back into a red one and after Andre is turned into a red lum, all the other black lums immediately change back.
• Resident Evil is replete with these, both in the form of literal viruses, and the Las Plagas parasites.
• In Resistance: Fall of Man, an alternate history first-person shooter, the aliens known as the Chimera use a mutagenic virus that causes humans to fall into a coma and undergo horrific physical mutations that turn them into Chimera soldiers. These mutated soldiers retain no trace of their former personality and are completely subservient to the elite Chimera known as Angels; in fact, Chimera soldiers die if their psychic link with the Angels is severed. They needed a Conversion Center to fully complete the transformation in a reasonable amount of time. In R2, infected people simply have cocoons built around them and are left to transform on their own.
• The R-Type series eventually evolves the Bydo into something like this, although this isn't their favored modus operandi; usually, they simply evolve, replicate, and reproduce to improve themselves and strengthen their numbers, but given the opportunity, they will assume forms that are designed to infect and assimilate enemy technology and personnel. R-Type Delta had a good example of this in several of its ships and one of its Multiple Endings, and R-Type Final and R-Type Tactics/Command use this as a turning point in their respective storylines (much more the latter, with it even affecting gameplay). The R-13A Cerberus ending in Delta has your ship fail to escape the Bydo dimension and become part of a Bydo Tree. This same ship is encountered in Final as an Optional Boss. This happens to you again in one ending in Final, where you even fight against your own former allies. The thing is that you don't even realize you were infected by it.
• Silpheed has an entire ship — the ship that refueled you about ten seconds ago, to boot — get taken over by an alien virus and turns into not only an enemy alien, but also That One Boss.
• Slime Rancher:
  • When a slime^note such as a Honey Slime eats the plort of a different species,^note such as a Hunter Slime it becomes a Largo Slime.^note A Honey Hunter Largo, in the example case. The Largo slime can produce its original plort in addition to the plort of the species it hybridized with, as well as inherit their diet and favorite food. This can be taken advantage of, since combining a rare slime species with a more common one provides easier access to its plorts ^note Hunter Slimes are rare and have a rare favorite food, while Honey Slimes are easier to find, are equally valuable, and their favorite food is readily available and farmable. Also, largo slimes made with Hunter traits start feral, so hope their stomachs aren't full and you have some chickens.
  • Averted with The Tarr.^note The result of a Largo Slime eating yet another different plort. When a slime is eaten by a Tarr, the slime doesn't become a tarr itself. Rather, the Tarr expands, and splits in two, creating a clone that is completely unrelated to the victim.
• StarCraft: The Zerg Swarm employs a hyper-evolutionary virus with the ability to hybridize the infected's DNA with Zerg DNA to create new soldiers for the Swarm. Most infested Terrans end up deformed zombies with their minds consumed by the Hive Mind of the Swarm, though a certain few retained their free will and became leaders — most notably Kerrigan and Stukov.
• Star Fox: Assault has the Aparoids, a robotic insect colony from another dimension that infects both biological creatures and mechanical objects. A prime example of a victim is Pigma Dengar, who is fully assimilated by the aparoids, effectively killing him before he is destroyed by Fox. General Pepper nearly suffers the same fate.
• Star Wars Legends:
  • Knights of the Old Republic has rakghouls, deformed mutants with infectious bites, living in the Undercity of Taris. The player character cannot be infected, but several infected NPCs are seen transforming. In some cases, it can be prevented with a dose of rakghoul serum, but once the victim has actually been transformed, they must be killed. Interestingly, when the player character or a party member is bitten, they can be poisoned and take standard poison damage, and there is an instance where you save an NPC and he has been bitten and poisoned, but no one comments on this. This may mean that the rakghoul disease can be avoided outright if treated immediately. In the comics, it was revealed that the rakghoul disease was concocted by a Sith who made a talisman that instantly transformed humans into rakghouls which he could control, getting them to use their old skills, like weaponry. Comics taking place between the movies of the original trilogy had a fallen Jedi using this talisman on various heroes, including a member of The Remnant.
  • By the time of Star Wars: The Old Republic, set over three hundred years later, it's revealed that the rakghouls survived the bombing of Taris and now are not only capable of infecting people, but breeding independently, leading to hordes of rakghoul that can be seen from orbit. It then goes From Bad to Worse with the reveal that the virus has similarly evolved over the centuries, rendering the rakghoul serum ineffective against the new strain. Now the virus can affect players during a certain world event, but it is affected by Gameplay and Story Segregation; stage 1 infection causes frequent coughing fits, after 10 minutes it progresses to stage 2 which causes them to be more frequent and also adds Glowing Eyes, then after 10 more minutes the infectee begins to mutate before violently exploding. You can obtain a vaccine to protect yourself from infection for 6 hours after it's administrated.
• In Strife, the virus arrived via a massive comet impact. Those who weren't wiped out begin to mutate, hearing the voice of an alien monster and causing their bodies to rot. The Evil Empire Religion of Evil that worships the monster uses cybernetics to maintain their self-destructing bodies.
• Subnautica has the Kharaa Bacterium, a virulent and deadly alien plague. Creatures infected with Kharaa feature green glowing cysts.
• In Subterrain, a mysterious "infection" has wiped out a colony on Mars, turning people into violent monsters and leaving only one known survivor: the game's protagonist, Dr. Albert West. Exploring the derelict colony space uncovers several Apocalyptic Logs that slowly piece together the backstory. A set of such logs in the final area reveal the origin of the infection: it's a modification of the nanotechnology originally developed by Dr. West to treat his wife's Alzheimer's disease. A co-worker stole the tech to sell it, but their boss, Jeff Murray, became obsessed with using it to create a new race of Martians. Jeff used it to mutate both himself and Dr. West's wife Jennifer into horrible monstrosities that "psychically" control the horde. In the final confrontation with the transformed Jennifer, she asks Albert to join her. He can accept the offer and become a sort of "father" to the Martians.
• Both System Shock and its sequel feature enemies infected by The Virus. In the first game, the hybrids are subservient to SHODAN, but in System Shock 2, they're controlled by the Hive Mind of "The Many".
• In Uncharted: Drake's Fortune, El Dorado is a giant golden statue that turns out to be a golden sarcophagus containing a mummy, which carries a plague. Anyone who opens the sarcophagus is exposed to infected dust that transforms them within seconds of contact into a feral monster that attacks anyone else on sight. Realising this would lead to a Zombie Apocalypse, Francis Drake had the Spanish colony flooded and destroyed all the boats to prevent the spread. Later the city and the sarcophagus were discovered by a Nazi U-boat crew and they were infected as well. The Big Bad of the game meets his end when he opens the statue up and quickly turns.
• Warcraft:
  • The Lich King produces a virus which kills humans, then resurrects them as undead loyal to him. There is also a faction of Undead, the "Forsaken", who have broken free of the Lich King's control and have regained their free will.
  • In World of Warcraft, the Old Gods' Curse of Flesh "corrupted" the creations of the Titans on Azeroth into fleshy beings like themselves. In other words, every human, dwarf, gnome, and trogg (and possibly a few other species too) is "infected" by The Virus!
• Warframe: The Technocyte Plague was originally created as a weapon by the Orokin to fight the Sentients, but it quickly got out of hand. Not only it does not work against its intended enemy — the Sentients are immune to infection by the Plague — but it infects both living flesh and machinery, turning them into horrifying amalgamations of twisted flesh. Whenever the Infested show up, everyone drops everything to fight them. The Tenno are fortunately also immune to infection. This is because they are already Infested. Since the Sentients could control Orokin technology, the Orokin needed a non-technological solution. They infected people with carefully controlled cultures of it, granting them superhuman strength, endurance, and durability. These were the first warframes.
• In Zampanio Sim, Lord Dark's daughter Kasane creates this as a backup plan if she doesn't get nuclear warheads or legions of doom fast enough. The virus is very similar to the Matrix example above, it makes people vomit a sticky light pink liquid that covers their body, and then [[Clone by Conversion converts them into Kasane, except with added cat ears and a cat tail, that have the goo dripping off of them.

Webcomics

• The Dragon Doctors face their first real challenge when attempting to cure a patient who has a "Crax Parasite" inside him, a horrible, cancerous growth that will eventually consume his body and mind. The four magical doctors each make use of their full abilities to cure the disease. Kili the shaman occupies the patient's mind in a dream world while the others operate, and it is revealed when the Crax invades the dream that it's the vehicle of the consciousness of a man who wants to live forever.
• The revenants from Girl Genius are a bioweapon devised by a Mad Scientist, produced by devices called hive engines. When activated, the devices release a queen "Slaver Wasp" that almost immediately produces hundreds of soldier wasps (insectoid, non-flying killing machines the size of a big dog). They then make a perimeter and drive everyone inside to the center, where the queen releases a horde of tiny wasps that fly down your throat and control your brain. These newly created revenants act as zombie guards for the hive while the warriors corral in more humans. Additionally, the revenants are completely loyal to the creator of the hive engine, making them an excellent device for assembling instant armies of Mooks. The revenants are the exception. Most people infected go about their lives normally... but completely obedient to the Slaver Wasp creator.
• In The Kingfisher, the vampire condition can be communicated. It usually doesn't affect the mind of its victims directly, unless they become too hungry for blood.
• Nomura Syndrome in Manly Guys Doing Manly Things started as gene therapy to keep men looking young, but Gackt modified it to spread and turn men into the Bishōnen type of man. It's later noted that there are other viruses out there, one to turn boys into the rugged manly type (think American Kirby Is Hardcore in virus form) and another to turn people into My Little Ponies. It turns out that the cure is Canadian healthcare.
• The Legion from MSF High are a legion of Green Skinned Space Babes who, when forced to fight, turn their attackers (whether male or female to begin with) into Green Skinned Space Babes who see things their way. That's in the present; they worked similarly in the past, but replace "attackers" with "defenders" and "see things their way" with "lose all of their original personalities and fight mindlessly for the Queen".
• Skin Horse:
  • Unity, one of the protagonists, is a non-virulent virus. She's a collection of nanobots suspended in fluid, and anything injected with her becomes her completely... but she can't actually fight off the immune systems of the living at all, so anything not dead she tries on ends up vomiting her out after a short while. And she has no method of spreading outside of purposeful injection.
  • The Cyprus, and her daughter Venus, are living plant matter that can reanimate corpses as zombie drones. In the Mirror Universe, Unity and Venus combined to form the Great Unity, also known as the Biomass, a virulent strain that absorbed much of the population... until it kicked its universe's Unity out and decided it was going to be a selective all-devouring singularity.
    Dan/Biomass: You'll all be outside begging to be assimilated!
• The Dimension of Pain demons from Sluggy Freelance possess a spear that can turn human beings (and ferrets, apparently) into demons, and they use it frequently during their invasion of the Dimension of Lame. However, since the spear can't completely get rid of the humans' inherent wussiness, the result is an army of pretty wussy demons. A human-made version (or is it...?) has appeared in the main dimension now. None of the resulting demons has been seen for more than a strip or two, so it remains to be seen if the results are Lame or otherwise weaker than real demons.
• In Superidol, computer-generated Idol Singer Rei Rei is the memetic version of this, with billions doing everything they can to be her, until the whole world revolves around her.
• Surviving Romance features the outbreak of a virus that turns everyone infected into a mindless, violent zombie.
• Sweet Home (2017) has the monsterization Virus, which — unlike most of the examples on this page — doesn't have a single, general direction of mutation. Instead, those that are infected by it are mutated accordingly to their desires. For example, "Muscle" who is all but outright implied to have been a fitness nut of sorts (or desperately craved for muscles but could never build them) constantly craved for strength resulting in his unique mutation. The Virus spreads incredibly fast and by the times the symptoms kick in, it is usually too late. Even the protagonist is infected by this Virus. The origins of the Virus itself are so enigmatic that even in-universe, characters are immersed in Epileptic Trees with theories ranging from Gaia's Vengeance to alien involvement.
• Zombie Waffe has LARS (Likasi Acute Rabies Syndrome), a new form of rabies which turns those infected into zombies.

Web Originals

• In Atop the Fourth Wall, Missing Number is portrayed as an Eldritch Abomination version of this, determined to consume all universes until nothing remains but itself. Linkara pulls an And Then What?, which gets it to wonder about what would happen if it died, and it elects to find out.
• The Federal Vampire & Zombie Agency: Vampires, zombies and werewolves are caused by a variation of a virus from the family of rabies.
• The Infestation of The Nutty Joes: A giant brain crash lands in the middle of a quiet country village, hatching a crazed creature whose laughter soon rings out throughout all of mankind.
• In The Magnus Archives, characters start finding strange silver worms. It becomes apparent that these are controlled by Jane Prentiss, and infest people and either kill them or turn them into zombie-like servants (or both).
• Orion's Arm has many different kinds, most of which are at least low grade Nightmare Fuel:
  • Blights are deranged intelligences which try to consume and convert all minds and processing platforms they can reach into likenesses of their own mind. Many of these occur when the original mind attempted transcendence, which has the unpleasant side effect that the Blight is also a transapenient with all of the godlike mental abilities that implies... being able to totally outthink and control its former peers being perhaps the least of their new skills. The Amalgamation is a horrifyingly powerful blight capable of subverting even powerful Archai.. hugely capable god-like intelligences that are vastly better equipped to defend against Blights than mere mortals.
  • Affines are a sort of sentient virus for highly advanced transapients. Hive Mind type transapients with subminds dealing with perception are most at risk... imagine your eyes and ears became malignly sentient because of something you saw or heard and then went on to slowly trick you into doing what the virus wanted. Human sensory systems are entirely too primitive for affines to work on them, but the seemingly benevolent AI overlord of a planetary colony might one day start turning into a brutal dictator and slaughter huge numbers of its former citizens without a care.
• In the Prolecto series of stories, this is how the Succubus transformation spreads. In a subversion, people are generally pretty much themselves... except for the compulsion to spread, which wears off after they spread once, unless they take a deep breath. Unfortunately, at least one of them has Contractual Genre Blindness.
• SCP Foundation
  • SCP-008 ("Zombie Plague") is probably the simplest and most self-explanatory example. It's a prion disease that turns people into flesh-eating zombies.
  • SCP-217 ("The Clockwork Virus") is basically The Virus plus Clockwork Eats Your Soul.
  • If any part of SCP-299 ("Infectious Tree") (even a single cell) touches or is inserted into a plant or animal, it will change the plant or animal into another SCP-299. The total time required depends on how large the plant or animal is.
  • A mind-only variant is SCP-571 ("Self-Propagating Infectious Pattern"): a Brown Note which causes its victims to make copies of it and show it to other people.
  • SCP-610 ("The Flesh that Hates") is a disease that mutates infected individuals in a Flood-like manner.
  • Touching SCP-630 ("Black Glacier") causes the victim to slowly transform into more of the strange ice.
  • After the touch of a SCP-1120 ("Freeze Tag") has petrified a human being, that human becomes a new SCP-1120.
  • If any living creature consumes SCP-1361 ("Animal By-Product"), it will be converted into more SCP-1361 over a period of 4-6 hours.
  • Any living creature whose form is taken by SCP-1536 ("Doppelgängers") will become a new SCP-1536 after it dies.
  • Anyone who breathes in SCP-2009-02 ("Thomas Hoang") spores created by SCP-2009-01 will become an example of SCP-2009-01 in 8-9 days.
  • SCP-2650-B ("Pediatric Pupaphobia") is the body of a former ventriloquist and magician who is still alive despite having a wooden sphere in place of his brain. If he can get a preadolescent child (between the ages of 5 and 9) alone, he can change them so that they're like him and under his control.
• In Swarm on the Somme, the Grex have a subspecies of small beetle-like creatures which bite people, infecting them with something which rewrites their DNA, turning them into zombie-like Grex-human hybrids controlled by the Hive Mind.
• The world of Taerel Setting has the kin'toni virus, a sickness made in a lab to make super soldiers. In a few weeks it turns the infected into a kin'toni, a strong, fast, and deadly predator. It is unknown if there is a cure as it is never brought up.
• The Computer Virus from We Are Our Avatars. In the past, it's infected many of the robotic characters, and most likely counts as Nightmare Fuel.
• The "Weegee virus" meme involves Weegee turning people into clones of himself with his stare, resulting in him making a big army. These clones also have a stare, making it a true virus.
• Whateley Universe: The Palm is a living artificial intelligence in the internet, trying to replicate and wipe out all human life. In a much creepier variant, in the story "The Op", this is what the heroes face, complete with Body Horror and Womb Level.

Western Animation

• The Avengers Assemble episode "Hulked Out Heroes" features A.I.M. creating a "gamma virus" that infects all of the Avengers except Black Widow and Hulk himself (who is obviously immune). The virus transforms the heroes into Hulking versions of themselves, and gradually makes them bigger, stronger, and more mentally unstable as time passes, with the eventual goal being total disintegration.
• Ben 10: Alien Force: The Xenocites transforms carbon-based lifeforms into a DNAlien under the thrall of the Highbreed. Thankfully, the Omnitrix has the power to revert the genetic damage and restore the original form of the victims.
• Played for Laughs in an episode of Camp Lazlo. It's learned in this episode that when Samson gets sick, his germs can cause others to at first, get sick, and then end up looking a lot like a hamster who is sick.
• In Code Lyoko, some of XANA's attacks follow this route, the specter first possessing one animal then spreading the control to others (rats in "Plagued", wasps in "Swarming Attack"). In "Attack of the Zombies", a possessed Kiwi can transmit The Virus to humans, Zombie Apocalypse-style.
• Codename: Kids Next Door: Count Spankulot's ability to turn other people and stuffed animals into spank-happy vampires. Instead of the traditional vampire bite, he spanks his victims without his gloves, and the only way this curse can be reversed is having the victim spank back the vampire who spanked him/her or spank the original vampire, Count Spankulot himself. No spanking, however, can be done unless the individual has broken a rule. This is demonstrated in the episode "Operation: L.O.C.K.D.O.W.N." when he lures Numbuh One into his jail cell and the latter goes on to spread his curse to the others during a Lockdown of the Treehouse. However, when this happens again in Operation: V.I.D.E.O.G.A.M.E., it has the transformation be reversed with a few hits of a S.P.L.A.N.K.E.R.
• The Fudd from Duck Dodgers, a parody of the Flood which transforms people into goofy-looking Elmer Fudds with speech impediments.
• Futurama:
  • A robot from a planet of robots fears that humans are The Virus in the episode "Fear of a Bot Planet".
    Robot: Is it true that humans sneak into your room at night, drain your fluids, and turn you into a human?
  • The Brain Slug:
    Hermes: The flight had a stopover on the Brain Slug Planet. Hermes liked it so much he decided to stay of his own free will.
• A multi-episode arc of Guardians of the Galaxy (2015) features Peter Quill and company having to deal with a breakout of the "Venom" symbiotes from one planet nearly infesting a highly populated one and then overrunning Asgard, transforming all the Asgardians except Heimdall.
• In the Phineas and Ferb Halloween Episode "Night of the Living Pharmacists", Dr. Doofenshmirtz accidentally makes one of these, with zombie-like copies of himself chanting "lots of me..." roaming all over Danville, turning anyone, including cameos, animals, and the main characters into a zombie pharmacist-looking guy with just a touch.
• In The Pirates of Dark Water, the eponymous Dark Water had the ability to kill people outright, or corrupt them into mutated minions or mindless slaves. In one of the more Nightmare Fuel-laden episodes, an elderly woman tries ingesting a drop of it in a youth potion, and it winds up consuming her completely from the inside.
• The Real Ghostbusters:
  • One of the recurring villains of the show, the Grundel, is a green-skinned ghost that preys upon badly-behaved children. Any child who willingly accepts the Grundel's influence slowly transforms into a copy of it and in turn seeks out other kids to infect.
  • "No One Comes to Lupusville" culminates in a group of werewolves (who can turn bitten victims into werewolves) fighting their enemies, a group of vampires (who can turn their bitten victims into vampires). As you might expect, the four heroes decide to get the hell out of there and not look back before it gets worse.
• ReBoot: Daemon is a literal software virus, as are Megabyte and Hexadecimal. Daemon and Megabyte match this trope better, as they have the ability to infect the system's sprites and convert them into their loyal soldiers.
• In the Regular Show episode "Guy's Night", anyone who drinks a gallon of milk without holding the empty jug over the head is sent to a white room full of white creatures that turn anyone they bite into one of them.
• In the Rick and Morty season 6 premiere, Mr. Frundles turns anything it bites into another Mr. Frundles, which spreads very quickly until the Earth itself becomes a Mr. Frundles. Rick opts to move his family into another universe rather than bother trying to fix it.
• The Samurai Jack episode "The Aku Infection" deals with Jack being infected by Aku's spirit, which begins to transform Jack into Aku from within. Jack had to defeat Aku in a Battle in the Center of the Mind to purge himself, drawing on his experiences and the good he's done in the future for power. Aku never stood a chance. (The strangest part is, Aku never intended to do it to Jack; it occurred by accident when the villain simply sneezed on his foe during a battle, because he was sick with a terrible cold. The only time he does this intentionally is en masse during the finale on a portion of Jack's allies.) However, Season 5 reveals that beings like the High Priestess can drink a whole chalice of what Jack swallows without suffering a horrific transformation due to being so morally depraved.
• In one episode of The Secret Show, Doctor Doctor creates a zombie virus that instantly infects someone if they utter the words "yes" and "no".
• Skeleton Warriors: Baron Dark can change anyone not "pure of heart" into a Skeleton Warrior.
• Super Robot Monkey Team Hyperforce Go!: The Skeleton King generates Mooks with one.
• The Tick: When reminiscing about past adventures, Captain Decency remembers the time a villain built a superweapon known as the "Ray Gun". This gun functioned by turning anyone it shot into a duplicate of "some guy named Ray", depicted as a gas station attendant with the nickname "Ray" on his coveralls. Cue incredibly creepy Twilight Zone-style black-and-white shot of a town filled with identical Rays saying "Hi, I'm Ray!" to each other over and over. Captain Decency then begins to reminisce about a similar adventure involving a "Tommy Gun" before being cut off.
• Transformers:
  • The Transformers has the Hate Plague from Outer Space which was unleashed upon the Earth. At first, it appears to make those infected fight others and themselves, but later on, it just appears to make them act like jerks with the intent of infecting others. Either way, the last known hope to the world, nay, universe is to revive Optimus Prime. It works, of course, and even Galvatron is thankful enough to call for a truce. For now. Previously in the same season, the Transorganic energy-leech threatened to spread the robotic equivalent of vampirism to all of Cybertron.
  • Much later, in Beast Machines, technomatter made with the Key to Vector Sigma has much the same effect — when the Maximals are zapped with the Key, they became both contagious and mentally unstable, and tried to infect each other.

Real Life

• Viruses, of course. They tend to do it on a microscopic scale; a popular method is for a virus to inject its genetic material into a cell, which corrupts/mutates it, making it produce more viruses inside itself. It then bursts, spreading many more viruses throughout the body and killing the cell in the process.
  • Bacteriophages work the same way, being viruses that target bacteria.
  • Mycoviruses are another class of viruses that specializes in targeting fungi.
  • Filoviruses (Marburgvirus and the various Ebolaviruses) do the same thing. Only to humans, at the human level. Richard Preston's The Hot Zone provides very graphic descriptions of what these viruses do to their hosts. The scariest part is that it's non-fiction. Well, sort of nonfiction — the book provides a very well-written and graphic account of a man infected with Marburgvirus "crashing," but from there on becomes a very dry and rather misleading history of the Reston Ebolavirus outbreak (which is non-infectious in human beings), and makes some rather dramatic misrepresentations of EBOV's level of infectivity — EBOV is indeed very infectious, but also very difficult to transmit and generally requires fluid contact with an infected person who is symptomatic.
    • ...except Reston was an airborne virus unlike human infecting versions. That's why it scared the shit out of scientists who didn't know at the time that the virus was non-lethal. It was still capable of infecting humans (workers at the site tested positive for Ebola virus anti-bodies) it's just that they weren't symptomatic.
  • Rabies. It infects your brain, drives you mad, uses you to spread the disease, and kills you once it's done with you. Yup, a real-world equivalent of the Rage. Fortunately, it tends to kill within a week of showing symptoms, and although humans can (in theory) transmit it through a bite, the only confirmed human-to-human transmissions of rabies have so far occurred through organ transplants. Fortunately, as of 2021, the amount of people affected by these transplants number in the single digits.
  • COVID-19, while not the most lethal per se, is extremely contagious, and caught most of the world off-guard in late 2019 and most of 2020. Its sanitary, economic and social consequences might well end up defining The New '20s.
  • There are types of viruses known has retroviruses. The difference between them and regular viruses is that retroviruses use RNA to infect their host rather than DNA. Rather than hijack a cell to produce more viruses, the cell integrates the retrovirus's RNA into its own DNA. Then the infected cell continues on as normal, producing the retrovirus as well as undergoing normal cell splitting. Even if the immune system can fight off the retrovirus, it likely won't go after the infected cells because nothing else about the cell changes to trigger a reaction. Eventually enough cells carry the viral RNA that it overwhelms the body with the retrovirus. If that wasn't enough to keep you up at night, scientists believe that roughly 8% of human DNA is actually retrovirus infections that managed to propagate over time. Whether or not that DNA actually does something is another matter since they label it as "junk" DNA.
• Leprosy is an interesting subversion that was often thought of this way; fear of the disease goes as far back as 4000 BC, and was recognized in the civilizations of ancient China, Egypt, Israel, and India, mentioned in The Bible and discussed by Hippocrates. (As in, the guy whom the Hippocratic Oath is named after.) The disease (which is actually caused by bacteria) used to be dreaded for its deadly nature and supposed highly contagious properties, so much that leprosy sufferers received stigma and ostracism from the population at large, and laws were passed to keep sufferers away from other citizens. (This stigma is still present in India, the only place where the disease is still widespread.) In truth, leprosy is actually caused by unsanitary conditions (making it once-common among the impoverished) not truly more contagious than most diseases caused by bacteria, and is treatable with modern medicine.
• Prions are mis-folded proteins that act as The Virus to other proteins, converting them into prions. This can also become The Virus for organisms, if the proteins being converted happen to be located in the brain. And all prions have a 100% case fatality rate, so there is no cure.
  • The above-mentioned Kuru and Mad Cow disease are both examples of Prion disease. Prions are especially terrible because they are both incurable and untreatable. Even worse is that individuals can spontaneously develop prions!
  • The worst part is that prions tend to be thermostable, so heating the infected flesh does NOT make it safe to eat. That's why mad cow disease is bad, bad news — not only do you have to cull the infected herd to prevent further infection, but the dead flesh remains hazardous.
• Diseases can alter your behavior in ways to spread themselves, but you may not realize it. Malaria makes you too tired to fight off mosquitoes, for instance. Defensive reflexes designed to rid our bodies' airways of infection (coughing, sneezing) are also behaviors that tend to spread it to others.
• Some real-life Puppeteer Parasites do this. Some require one host to carry, and another host to reproduce in, and force their primary host into zombie-like behavior. Some even have ants climb onto grass stalks overhanging their hives and emit spores as they decompose to infect healthy ants. Sounds like Resident Evil 4 meets A Bug's Life, doesn't it?
• If certain theoretical conditions are met, stable strangelets — a hypothetical category of subatomic-scale particle — could convert any normal matter they contact into more strangelets, which could then go on to convert more normal matter, and so on.
• Botnets are a type of Computer Virus that are designed to do this-every computer a botnet infects is assimilated into the owner's network and becomes a tool for sending out more infected emails and whatever they require the processing power for. Bonus for the actual computer that directs the botnet being called a master control. A slightly older terminology calls the infected machines Zombies and either the controlling computer or the human(s) controlling it the Zombie Master.
• The word "infection" itself is something of a virus. Pay attention to the terminology used when holding conversations with a person about a story involving some kind of monster assimilating or impregnating its victims; chances are they will use the word "infection" instead of the more accurate words. Indeed, "infection" is spreading and killing every other similar word in the English language, and there's nothing you can do about it! Woe is the grammar Nazi! This is probably due to the vast popularity of zombie stories in the last decade or so.
• The Cordyceps genus of fungi grows in insects. It eventually kills the host by filling up its body cavity. Often, at the very end of the process, it forces its dying and deranged host to crawl to the top of a nearby high point and cling there until its death, at which point the fruiting bodies of the fungus emerge and spread their spores.
• Similar to Cordyceps is Massospora cidadina, an infectious fungus that specifically infects cicadas. After infection, the cicada's internal organs are devoured and replaced by the fungus, and their bodies begin to fall apart. The fungus, however, leaves the nervous system of the cicada intact, allowing it to control the cicada's dead husk. On the bright side, the spores of Massospora cidadina are only released every decade or so.
• The Sacculina barnacle is a parasite of crabs. The larval female form burrows into a crab, sterilises it, disables its regenerative mechanisms (because these use up nutrients that Sacculina wants for itself) and pokes a bit of itself out of the crab's thorax waiting for a male Sacculina. When the parasite's egg have been fertilised, the parasitised crab looks after the Sacculina eggs as if they were its own.
  • This is what happens when Sacculina parasitises a male crab. It castrates them and disrupts their hormonal balance causing it to act like a female crab, even to the point of doing female mating dances. Like genetically female crabs, it looks after the Sacculina eggs when they form.
• A very ironic case is swine influenza, or "swine flu". Many people think that they can catch this dangerous disease from infected pigs, and fear of it has led some countries to mass slaughter them. In truth, humans cannot catch this disease via casual contact with pigs (humans who work in that industry who butcher them might), but ironically, pigs can catch it via casual contact from humans.

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