In print

• The Amnion in Stephen Donaldson
  Stephen R. Donaldson
  Stephen Reeder Donaldson is an American fantasy, science fiction and mystery novelist, most famous for his Thomas Covenant series...
  
  's Gap Cycle
  The Gap Cycle
  The Gap Cycle is a science fiction story, told in a series of 5 books, written by Stephen R. Donaldson. It is an epic set in a future where humans have pushed far out into space in the name of commerce and follows two concurrent story arcs...
  
  .
• The Blight is a viral, parasitic superhuman intelligence in Vernor Vinge
  Vernor Vinge
  Vernor Steffen Vinge is a retired San Diego State University Professor of Mathematics, computer scientist, and science fiction author. He is best known for his Hugo Award-winning novels and novellas A Fire Upon the Deep , A Deepness in the Sky , Rainbows End , Fast Times at Fairmont High ...
  
  's novel A Fire Upon the Deep
  A Fire Upon the Deep
  A Fire Upon the Deep is a science fiction novel by American writer Vernor Vinge, a space opera involving superhuman intelligences, aliens, variable physics, space battles, love, betrayal, genocide, and a conversation medium resembling Usenet...
  
  .
• The slugs in Robert Heinlein
  Robert A. Heinlein
  Robert Anson Heinlein was an American science fiction writer. Often called the "dean of science fiction writers", he was one of the most influential and controversial authors of the genre. He set a standard for science and engineering plausibility and helped to raise the genre's standards of...
  
  's novel The Puppet Masters
  The Puppet Masters
  The Puppet Masters is a 1951 science fiction novel by Robert A. Heinlein in which American secret agents battle parasitic invaders from outer space...
  
  
• The Comprise, a software-mediated human hive-mind that has taken over Earth and is in a state of cold war with the rest of the human race, in Michael Swanwick
  Michael Swanwick
  Michael Swanwick is an American science fiction author. Based in Philadelphia, Pennsylvania, he began publishing in the early 1980s.-Biography:...
  
  's Vacuum Flowers
  Vacuum Flowers
  Vacuum Flowers is a science fiction novel by Michael Swanwick, published in 1987. It is an early example of the cyberpunk genre, and features one of the earliest uses of the concept wetware....
  
  .
• The Conjoiners, a race of cybernetic humans who share thoughts electronically and are dedicated to improving themselves through increasingly advanced technology. From Alastair Reynolds
  Alastair Reynolds
  Alastair Preston Reynolds is a British science fiction author. He specialises in dark hard science fiction and space opera. He spent his early years in Cornwall, moved back to Wales before going to Newcastle, where he read physics and astronomy. Afterwards, he earned a PhD from St Andrews, Scotland...
  
  's Revelation Space
  Revelation Space
  Revelation Space is a 2000 science fiction space opera novel by Welsh author Alastair Reynolds. It was the first novel set in the Revelation Space universe, although the then-unnamed universe had already been established by several published short stories....
  
  series of novels.
• The Culture
  The Culture
  The Culture is a fictional interstellar anarchist, socialist, and utopian society created by the Scottish writer Iain M. Banks which features in a number of science fiction novels and works of short fiction by him, collectively called the Culture series....
  
  novels by Iain Banks
  Iain Banks
  Iain Banks is a Scottish writer. He writes mainstream fiction under the name Iain Banks, and science fiction as Iain M. Banks, including the initial of his adopted middle name Menzies...
  
   mention assimilating life forms ("Aggressive Hegemonizing Swarms"), also those that are gladly assimilated. The Culture itself assimilates other cultures, but not by force.
• Drummers, a tribe of humans who share nanobots by exchanging bodily fluids, in Neal Stephenson
  Neal Stephenson
  Neal Town Stephenson is an American writer known for his works of speculative fiction.Difficult to categorize, his novels have been variously referred to as science fiction, historical fiction, cyberpunk, and postcyberpunk...
  
  's novel The Diamond Age
  The Diamond Age
  The Diamond Age: Or, A Young Lady's Illustrated Primer is a postcyberpunk novel by Neal Stephenson. It is to some extent a science fiction bildungsroman, focused on a young girl named Nell, and set in a future world in which nanotechnology affects all aspects of life. The novel deals with themes of...
  
  .
• Jarts, an alien race devoted to archiving all life and information in Greg Bear's
  Greg Bear
  Gregory Dale Bear is an American science fiction and mainstream author. His work has covered themes of galactic conflict , artificial universes , consciousness and cultural practices , and accelerated evolution...
  
   novels set in The Way
  The Way (Greg Bear)
  The Way fictional universe is a trilogy of science fiction novels and one short story by Greg Bear. The first novel was Eon , followed by a sequel, Eternity and a prequel, Legacy...
  
  multiverse.
• Oankali
  Oankali
  The Oankali are a fictional race of intelligent extraterrestrials in Octavia Butler's Xenogenesis book trilogy ....
  
   in Octavia Butler's Xenogenesis
  Xenogenesis
  Lilith's Brood is a collection of three works by Octavia Butler. The three volumes of this science fiction series were previously collected in the now out of print volume, Xenogenesis...
  
  trilogy, who can seduce unwilling humans to create human-Oankali "construct" hybrids.
• The Phalanx
  Phalanx (comics)
  The Phalanx are a fictional cybernetic species in the Marvel Comics universe. They have come in conflict with the X-Men and related groups on several occasions. They form a hive mind, linking each member by a telepathy-like system....
  
   from Marvel Comics
  Marvel Comics
  Marvel Worldwide, Inc., commonly referred to as Marvel Comics and formerly Marvel Publishing, Inc. and Marvel Comics Group, is an American company that publishes comic books and related media...
  
   perpetuate their race through the assimilation of other species.
• Yeerks and The One in Animorphs
  Animorphs
  Animorphs is an English language science fiction series of young adult books written by K. A. Applegate and published by Scholastic. Five humans, Jake, Marco, Cassie, Rachel, and Tobias, and one alien, Aximili-Esgarrouth-Isthill , obtain the ability to morph into any animal they touch. They name...
  
  .
• Gaia (Foundation universe)
  Gaia (Foundation universe)
  Gaia is a fictional planet described in the book Foundation's Edge and referred to in Foundation and Earth , by Isaac Asimov. The name is derived from the Gaia hypothesis, which is itself eponymous to Gaia, the Earth Goddess....
  
   in the latter Foundation novels of Isaac Asimov
  Isaac Asimov
  Isaac Asimov was an American author and professor of biochemistry at Boston University, best known for his works of science fiction and for his popular science books. Asimov was one of the most prolific writers of all time, having written or edited more than 500 books and an estimated 90,000...
  
  , an entity which unified all atoms of matter into a collective consciousness for the benefit of all.
• The Quizart from Frank Herbert's Dune
  Dune (franchise)
  Dune is a science fiction franchise which originated with the 1965 novel Dune by Frank Herbert. Considered by many to be the greatest science fiction novel of all time, Dune is frequently cited as the best-selling science fiction novel in history...
  
  , assimilate the people of the known universe to the religion of Muad'Dib as a means to wipe out all other religions and to increase the power of Muad'Dib.
• Starro
  Starro
  Starro is a fictional supervillain that appears in comic books published by DC Comics. The character first appeared in Brave and the Bold #28 , and was created by Gardner Fox and Mike Sekowsky....
  
   the Conqueror in the DC Comics
  DC Comics
  DC Comics, Inc. is one of the largest and most successful companies operating in the market for American comic books and related media. It is the publishing unit of DC Entertainment a company of Warner Bros. Entertainment, which itself is owned by Time Warner...
  
   universe. Can release spores to take mental control of populations and heroes.
• The Electric Church, a psuedo-religious organization made up of robotic "monks" with human brains in The Electric Church by Jeff Somers
  Jeff Somers
  -Literary career:Since 1995, Somers has published his zine The Inner Swine and has been a prolific contributor to alt.zines. The 21st century has seen Somers's transformation from an observational essayist into a science fiction writer of no small talent, "a gifted craftsman" with a "funky wit." ...
  
  .

In TV drama

• The Borg
  Borg (Star Trek)
  The Borg are a fictional pseudo-race of cybernetic organisms depicted in the Star Trek universe associated with Star Trek.Whereas cybernetics are used by other races in the science fiction world to repair bodily damage and birth defects, the Borg use enforced cybernetic enhancement as a means of...
  
   are a race of cyborg
  Cyborg
  A cyborg is a being with both biological and artificial parts. The term was coined in 1960 when Manfred Clynes and Nathan S. Kline used it in an article about the advantages of self-regulating human-machine systems in outer space. D. S...
  
  s in the Star Trek
  Star Trek
  Star Trek is an American science fiction entertainment franchise created by Gene Roddenberry. The core of Star Trek is its six television series: The Original Series, The Animated Series, The Next Generation, Deep Space Nine, Voyager, and Enterprise...
  
  universe. They are known within and beyond Star Trek fandom for their relentless pursuit of what they want to assimilate, their rapid adaptability
  Adaptation
  An adaptation in biology is a trait with a current functional role in the life history of an organism that is maintained and evolved by means of natural selection. An adaptation refers to both the current state of being adapted and to the dynamic evolutionary process that leads to the adaptation....
  
   to almost any defense, and their ability to continue functioning after what may seem a devastating or even fatal blow seemingly unaffected. As such, the Borg have become a powerful symbol in popular culture
  Popular culture
  Popular culture is the totality of ideas, perspectives, attitudes, memes, images and other phenomena that are deemed preferred per an informal consensus within the mainstream of a given culture, especially Western culture of the early to mid 20th century and the emerging global mainstream of the...
  
   for any juggernaut
  Juggernaut
  A juggernaut in colloquial English usage is a literal or metaphorical force regarded as mercilessly destructive and unstoppable.Originating in ca...
  
   against which "resistance is futile".
• Neural parasite or "blue gill" from the Star Trek universe. Parasitic being which tried to infiltrate Starfleet
  Starfleet
  In the fictional universe of Star Trek, Starfleet or the Federation Starfleet is the deep-space exploratory, peacekeeping and military service maintained by the United Federation of Planets . It is the principal means by which the Federation conducts its exploration, defense, diplomacy and research...
  
   by physically connecting with brains of high-ranking admirals within the organization (From TNG episode "Conspiracy").
• The Cybermen
  Cyberman
  The Cybermen are a fictional race of cyborgs who are amongst the most persistent enemies of the Doctor in the British science fiction television series, Doctor Who. Cybermen were originally a wholly organic species of humanoids originating on Earth's twin planet Mondas that began to implant more...
  
  , a cyborganic race introduced in 1966 in the TV series Doctor Who
  Doctor Who
  Doctor Who is a British science fiction television programme produced by the BBC. The programme depicts the adventures of a time-travelling humanoid alien known as the Doctor who explores the universe in a sentient time machine called the TARDIS that flies through time and space, whose exterior...
  
  . They take suitable human subjects and supplement or replace organic parts. Unlike the Borg, each Cyberman is an individual, but devoid of emotion or loyalty to their former life, with no chance for "reversion" to their original state.
• Kobali from the Star Trek universe. They reproduce by reanimating the dead of other species and converting them into Kobali.
• Also in Doctor Who, the episode School Reunion
  School Reunion (Doctor Who)
  "School Reunion" is the third episode in the second series of the British science fiction television series Doctor Who. It first aired on 29 April 2006. The episode's narrative takes place some time after the events of "The Christmas Invasion"...
  
   features the Krillitanes, bat-like creatures who absorb characteristics from other species which they have conquered.
• The carnivorous stingray-like aliens in the Doctor Who episode "Planet of the Dead".
• Stargate SG-1's
  Stargate SG-1
  Stargate SG-1 is a Canadian-American adventure and military science fiction television series and part of Metro-Goldwyn-Mayer's Stargate franchise. The show, created by Brad Wright and Jonathan Glassner, is based on the 1994 feature film Stargate by Dean Devlin and Roland Emmerich...
  
  Goa'uld
  Goa'uld
  The Goa'uld are a fictional symbiotic race of ancient astronauts from the American-Canadian military science fiction television franchise Stargate. The Goa'uld are parasites from the planet P3X-888, integrated within a host, most of the time human. The resulting creatures are a powerful race bent...
  
  , a race of parasites that enter the bodies of their hosts whom they then control, and Replicators
  Replicator (Stargate)
  In the military science fiction series Stargate SG-1, the Replicators are antagonistic self-replicating machines that propagate by ingesting the metals that make up civilizations and use them to create either blocks that form the bug-like version or smaller cells that compose the human-form...
  
  , a mechanical race that absorbs technology and annihilates entire galaxies for resources.
• Brain Slugs from Futurama
  Futurama
  Futurama is an American animated science fiction sitcom created by Matt Groening and developed by Groening and David X. Cohen for the Fox Broadcasting Company. The series follows the adventures of a late 20th-century New York City pizza delivery boy, Philip J...
  
  
• The orange glowing alien entities in Invasion
  Invasion (TV series)
  Invasion is an American science fiction television series that aired on ABC for only one season beginning in September 2005. Somewhat similar to Invasion of the Body Snatchers, the show told the story of the aftermath of a hurricane in which water-based creatures infiltrate a small Florida town and...
  
  
• Xenocytes from Ben 10: Alien Force
  Ben 10: Alien Force
  When it recalibrated it gained a more watch-like shape, a green wristband, became smaller and sleeker, and the face dial became black and green. The inside of the hourglass shape glows in different colors at special moments; these colors signify the state that the Omnitrix is presently in...
  
  
• The Invaders from Getter Robo: Armageddon
  Getter Robo Armageddon
  , often simply referred to as Change!! Getter Robo in Japan, is an original video animation released in 1998 by Bandai Visual, based on the manga and anime series Getter Robo, created by Go Nagai and Ken Ishikawa...
  
  , a race of extraterrestrial Invaders which have the power to possess humans, mutating them into hideous creatures, as well as survive even if reduced to tiny pieces. They can also assume any shape they want, as they are amorphous in nature. Their most distinctive features are their many eyeballs and protruding spikes.
• The Black Oil or Purity from The X-Files
  The X-Files
  The X-Files is an American science fiction television series and a part of The X-Files franchise, created by screenwriter Chris Carter. The program originally aired from to . The show was a hit for the Fox network, and its characters and slogans became popular culture touchstones in the 1990s...
  
  which is a sentient virus which infects humans and uses their body to grow a new life-form or alternatively can simply take control of the infected person

In film

• The Necromongers, in the film The Chronicles of Riddick
  The Chronicles of Riddick
  The Chronicles of Riddick is a 2004 American science fiction film which follows the adventures of Richard B. Riddick, as he attempts to elude capture after the events depicted in the 2000 film Pitch Black, and details his meeting with Jack and Imam, his escape from the prison planet Crematoria, and...
  
  .
• The "Thing" from the film The Thing.
• The Xenomorph
  Xenomorph (Alien)
  The Alien is a fictional endoparasitoid extraterrestrial species that is the primary antagonist of the Alien film series. The species made its debut in the 1979 film Alien, and reappeared in its sequels Aliens , Alien 3 , and Alien Resurrection , two crossovers Alien vs...
  
  s from the Alien
  Alien (film series)
  The Alien film series is a science fiction horror film franchise, focusing on Lieutenant Ellen Ripley and her battle with an extraterrestrial lifeform, commonly referred to as "the Alien"...
  
  films reproduces by implanting an embryo into a host creature, which then "chestbursts" out of the victim. In the first two movies, the hosts and resultant Xenomorphs were humans, but in the films Alien 3 and Alien vs. Predator
  Alien vs. Predator (film)
  Alien vs. Predator is a 2004 American science fiction film directed by Paul W. S. Anderson for 20th Century Fox and starring Sanaa Lathan and Lance Henriksen. The film adapts the Alien vs. Predator crossover imprint bringing together the eponymous creatures of the Alien and Predator series, a...
  
  - as well as the computer games Aliens versus Predator 2
  Aliens versus Predator 2
  Aliens versus Predator 2 is a science fiction first-person shooter computer game developed by Monolith Productions. It was published by Sierra Entertainment, and released through Fox Interactive for PC and Apple Macintosh computers in 2001...
  
  and Aliens vs. Predator: Extinction - the host creature was inhuman, giving rise to a Xenomorph that had assimilated attributes of the parent species.
• The pod people
  Pod People (Invasion of the Body Snatchers)
  Pod people is a nickname given to an alien species featured in the 1955 novel The Body Snatchers by Jack Finney, the 1956 film Invasion of the Body Snatchers, the 1978 remake of the same name and the 1993 film Body Snatchers.-History from the novel:The Pod People are a race of nomadic,...
  
   from Invasion of the Body Snatchers, its remakes in 1978
  Invasion of the Body Snatchers (1978 film)
  Invasion of the Body Snatchers is a 1978 science fiction film based on the novel The Body Snatchers by Jack Finney. It is a remake of the 1956 film of the same name. It was directed by Philip Kaufman and starred Donald Sutherland, Brooke Adams and Leonard Nimoy.A San Francisco health inspector and...
  
  , 1993
  Body Snatchers (1993 film)
  Body Snatchers is a 1993 American science fiction horror film and loosely based on the 1955 novel The Body Snatchers by Jack Finney. The film was directed by Abel Ferrara, starring Gabrielle Anwar, Billy Wirth, Terry Kinney, Meg Tilly, R...
  
  , and 2007
  The Invasion (film)
  The Invasion is a 2007 science fiction thriller film starring Nicole Kidman and Daniel Craig, directed by Oliver Hirschbiegel, with additional scenes written by the Wachowski brothers and directed by James McTeigue....
  
   and the original sci-fi
  Science fiction
  Science fiction is a genre of fiction dealing with imaginary but more or less plausible content such as future settings, futuristic science and technology, space travel, aliens, and paranormal abilities...
  
   novel
  Novel
  A novel is a book of long narrative in literary prose. The genre has historical roots both in the fields of the medieval and early modern romance and in the tradition of the novella. The latter supplied the present generic term in the late 18th century....
  
   The Body Snatchers
  The Body Snatchers
  The Body Snatchers is a 1955 science fiction novel by Jack Finney, originally serialized in Colliers Magazine in 1954, which describes the fictional town of Santa Mira, California being invaded by seeds that have drifted to Earth from space...
  
  . An alien race trying to conquer Earth by killing and replacing all humans (using plant-like "pods") producing indistinguishable copies, save for a lack of emotional behavior.
• Control Bug Caste of the Bug
  Bug (Starship Troopers)
  The Bugs are an extraterrestrial race in the novel Starship Troopers by Robert A. Heinlein, its film adaptation , sometimes also referred to as the Arachnids, although this is a misnomer, as the aliens are not related to Earth arachnids...
  
  s from Starship Troopers
  Starship Troopers (film)
  Starship Troopers is a 1997 American military science fiction film, written by Edward Neumeier , directed by Paul Verhoeven, loosely adapted from Starship Troopers, a science fiction novel by Robert A. Heinlein. It is the only theatrically released film in the Starship Troopers franchise...
  
  
• The program "Agent Smith" from The Matrix
  The Matrix
  The Matrix is a 1999 science fiction-action film written and directed by Larry and Andy Wachowski, starring Keanu Reeves, Laurence Fishburne, Carrie-Anne Moss, Joe Pantoliano, and Hugo Weaving...
  
  trilogy
• Two aliens in The Hidden
  The Hidden
  The Hidden is an American science fiction film produced and released in 1987 by New Line Cinema. The film was written by Bob Hunt and directed by Jack Sholder...
  
  

In computer and video games

• The Scurge of Scurge: Hive
  Scurge: Hive
  Scurge: Hive is an action-adventure video game by Orbital Media released for the Game Boy Advance and Nintendo DS in 2006. The game follows the protagonist Jenosa Arma, a female bounty hunter tasked with hunting a parasitic lifeform called the "Scurge" an alien entity capable of rapidly adapting...
  
  are a cellular assimilation organism that rapidly infect biological, mechanical, and even energy based systems. Anything thus absorbed has its intelligence (if there is any) transferred back to the Source, which is the spawner and collective hive mind of the Scurge virus. This allows the Source to reach sentience.
• Aparoids, a race of bio-technological organisms that were the central antagonist of Star Fox: Assault
  Star Fox: Assault
  Star Fox: Assault is a third-person shooter video game for the Nintendo GameCube developed by Namco and published by Nintendo. It is the fourth released title in the Star Fox series. It was released on February 14, 2005 in North America, on February 24, 2005 in Japan, on April 29, 2005 in Europe,...
  
  that sought evolution through assimilation (referred to in the game as "Aparoideation"). They are capable of assimilating both machines and living organisms. This continues the Star Fox series
  Star Fox series
  is a video game series published by Nintendo. The original game was a forward-scrolling 3D Sci-Fi rail shooter. Later sequels added more directional freedom as the series progressed. The game concept was inspired by a shrine to a fox god who could fly, which Shigeru Miyamoto visited regularly...
  
  ' tradition of referencing other science fiction works.
• The Omar are a race of cyborgs in the computer game Deus Ex: Invisible War
  Deus Ex: Invisible War
  Deus Ex: Invisible War is an action role-playing game developed by Ion Storm Inc. and published by Eidos Interactive. Released simultaneously for Microsoft Windows and the Xbox video game console on December 2, 2003, the game is a sequel to the critically acclaimed Deus Ex...
  
  . They assimilate humans into the Omar (though this is usually voluntary). The Omar are supposed to have a merged collective consciousness, though many Omar will refer to themselves as "I" instead of "We." This seems to show that the Omar still retain some individuality.
• The Zerg from the game StarCraft
  StarCraft
  StarCraft is a military science fiction real-time strategy video game developed by Blizzard Entertainment. The first game of the StarCraft series was released for Microsoft Windows on 31 March 1998. With more than 11 million copies sold worldwide as of February 2009, it is one of the best-selling...
  
  are an insectoid race that assimilate (usually referred to in-game as "infesting") or destroy every race that they come into contact with. Their attempt to overpower and assimilate the Protoss forms a major part of the storyline of the game.
• The Undead Scourge in the Warcraft
  Warcraft
  Warcraft: Orcs & Humans is a real-time strategy game , developed by Blizzard Entertainment and published by Blizzard and Interplay Entertainment. The MS-DOS version was released in November 1994 and the Macintosh version in late 1996. Sales were fairly high, reviewers were mostly impressed, and the...
  
  universe is a massive army of living dead creatures residing on the continents of Lordaeron and the Eastern Kingdoms. They spread a plague of undeath that turns all it infects into Undead. They are under the absolute control of the leader of the scourge, the Lich King. They seek to destroy all life.
• The Flood
  The Flood (Halo)
  The Flood are fictional parasitic alien life forms in Bungie's Halo video game series. They are introduced in Halo: Combat Evolved as a second enemy faction alongside the Covenant, and return in sequels Halo 2, Halo 3, and Halo Wars...
  
   from the Halo: Combat Evolved
  Halo: Combat Evolved
  Halo: Combat Evolved, frequently referred to as Halo: CE, or Halo 1, is a first-person shooter video game developed by Bungie and published by Microsoft Game Studios. The first game of the Halo franchise, it was released on November 15, 2001 as a launch title for the Xbox gaming system, and is...
  
  line of video games is a parasitic life form consisting of an Infection Form that burrows into a life form's skin and takes control of their neural pathways, transforming them into a Flood Combat Form. The host is eventually made into a Carrier Form, to create more Infection forms. The Flood are capable of destroying all life and have only been stopped by the Halo
  Halo (megastructure)
  Halos are fictional megastructures and superweapons in the Halo video game series. They are referred to as "Installations" by their AI monitors, and are collectively referred to as "the Array" by the installations' creators, the Forerunners...
  
  s.
• In Half-Life 2
  Half-Life 2
  Half-Life 2 , the sequel to Half-Life, is a first-person shooter video game and a signature title in the Half-Life series. It is singleplayer, story-driven, science fiction, and linear...
  
  the Combine
  Combine (Half-Life 2)
  The Combine, also referred to as the Universal Union, is a multidimensional empire, which serves as the primary antagonistic force in the Half-Life video game series, developed by Valve Corporation. The Combine consist of alien, synthetic, and human elements and dominate Earth...
  
   assimilate humans to Combine soldiers for their military, or workers called stalkers. The Combine's final goal is to assimilate all of Earth's population, drain their natural resources, and move on. Also appearing in Half-Life and Half-Life 2 are Headcrabs, a parasite resembling a large crab or tick. Headcrabs attach to the head of prey, mutating the subject and taking control of the subject's body, resulting in a Zombie
  Zombie
  Zombie is a term used to denote an animated corpse brought back to life by mystical means such as witchcraft. The term is often figuratively applied to describe a hypnotized person bereft of consciousness and self-awareness, yet ambulant and able to respond to surrounding stimuli...
  
  -like entity called headcrab zombies. Headcrabs have been seen attached to humans and Combine.
• The Tyranids
  Tyranids
  The Tyranids are a fictional race from the Warhammer 40000 tabletop game and its spin-off media. They are known to the Imperium generally as Tyranids, because Tyran is the first known planet they devoured and where they were first encountered...
  
   in Games Workshop
  Games Workshop
  Games Workshop Group plc is a British game production and retailing company. Games Workshop has published the tabletop wargames Warhammer Fantasy Battle and Warhammer 40,000...
  
  's Warhammer 40,000
  Warhammer 40,000
  Warhammer 40,000 is a tabletop miniature wargame produced by Games Workshop, set in a dystopian science fantasy universe. Warhammer 40,000 was created by Rick Priestley in 1987 as the futuristic companion to Warhammer Fantasy Battle, sharing many game mechanics...
  
  setting absorb all organic life and material on a planet, absorbing the DNA and using it to improve their biological design and battle prowess.
• Metroid Prime from Metroid Prime
  Metroid Prime
  Metroid Prime is a video game developed by Retro Studios and Nintendo for the Nintendo GameCube, released in North America on November 17, 2002...
  
  assimilated numerous Space Pirate weapons, making them an integral part of its body.
• The Ing from Metroid Prime 2: Echoes
  Metroid Prime 2: Echoes
  Metroid Prime 2: Echoes, known as in Japan, is a first-person, action-adventure video game developed by Retro Studios and published by Nintendo for the GameCube video game console. It is the seventh game in the Metroid series, a direct sequel to Metroid Prime, and the first game in the series with...
  
  , who merge with animals, sentients or technology and transform them into lethal "darklings".
• The X from Metroid Fusion
  Metroid Fusion
  , also known as Metroid 4, is an action-adventure video game published by Nintendo for the Game Boy Advance. It was released in North America, Europe, and Australia in November 2002, and in Japan in February 2003. The game is the fourth main installment in the Metroid series...
  
  , who possess organic life and matter and clones them.
• The Strogg from Quake 2 and Quake 4
  Quake 4
  Quake 4 is the fourth title in the series of Quake first-person shooter computer games. The game was developed by Raven Software and published by Activision. Raven Software has collaborated with id Software, the creators and historical developers of preceding Quake games...
  
  , who violently assimilate organic creatures to make them lethal monsters.
• The Many from System Shock 2
  System Shock 2
  System Shock 2 is a 1999 first-person action role-playing video game, designed by Ken Levine for Microsoft Windows. The title is a sequel to the 1994 PC game System Shock, and was co-developed by Irrational Games and Looking Glass Studios...
  
  
• In Resistance: Fall of Man
  Resistance: Fall of Man
  Resistance: Fall of Man is a first-person shooter video game for the PlayStation 3. It was developed by Insomniac Games and published by Sony Computer Entertainment. The game is set in an alternate history 1951, and follows Sgt...
  
  , the Chimera, the game's main antagonists, are a race of unknown origin who perpetuate their species by assimilating humans. The Chimera infect humans with a transformative virus, which induces coma
  Coma
  In medicine, a coma is a state of unconsciousness, lasting more than 6 hours in which a person cannot be awakened, fails to respond normally to painful stimuli, light or sound, lacks a normal sleep-wake cycle and does not initiate voluntary actions. A person in a state of coma is described as...
  
   on human victims. Infected humans are then taken to "conversion centers", where they are transformed into different types of Chimeran creatures. The bigger Chimeran creatures are actually composed of multiple human bodies, making humans no more than "modelling clay" for the creation of new creatures.
• The Beast from the game Homeworld: Cataclysm
  Homeworld: Cataclysm
  Homeworld: Cataclysm was originally developed in 2000 as an expansion of Homeworld, but was released as a stand-alone game. It was published by Sierra Entertainment, as was the original, but it was developed by Barking Dog Studios.-Gameplay:...
  
  is a viral entity that infects starships and adds them to its hive-mind. The infection, spread via a "charged particle beam" or by simple physical contact, converts the ship's crew into a form of bio-circuitry which melds with the ship's system and is used to control it. This bio-circuitry is often visible on the outside of the ship's hull, lending the craft a ghoulish "zombified" appearance.
• The Brains from the arcade game Robotron 2084 turn humanoids into Progs, fast-moving agents of destruction that mercilessly home in on the player.
• In Mass Effect
  Mass Effect
  Mass Effect is an action role-playing game developed by BioWare for the Xbox 360 and Microsoft Windows by Demiurge Studios. The Xbox 360 version was released worldwide in November 2007 published by Microsoft Game Studios...
  
  , the Geth are a race of synthetic life who convert the dead bodies of organic life into mechanical husks, though these husks are only used for psychological warfare against the organic species and the technology to do this is not their own.
• The hobbes from Fable
  Fable (video game)
  Fable is an action role-playing video game in the Fable series. It was developed for Xbox, Mac OS X, and Windows platforms, by Big Blue Box, a satellite developer of Lionhead Studios, and was published by Microsoft. The game shipped for Xbox on October 14, 2003...
  
  and Fable II
• The Fold from Marvel Ultimate Alliance 2 who are a nanite-based collective mind made up of numerous individuals including super-heroes and super-villains.

On the web

• The Amalgamation an aggressive empire composed of individual intelligences in the Orion's Arm
  Orion's Arm
  Orion's Arm, is a multi-authored online science fiction world-building project, first established in 2000 by M. Alan Kazlev, Donna Malcolm Hirsekorn, Bernd Helfert and Anders Sandberg and further co-authored by many people since...
  
   space opera
  Space opera
  Space opera is a subgenre of science fiction that emphasizes romantic, often melodramatic adventure, set mainly or entirely in outer space, generally involving conflict between opponents possessing advanced technologies and abilities. The term has no relation to music and it is analogous to "soap...
  
  . "Hegemonizing transapient assimilationist swarm"

In various media

• Vampire
  Vampire
  Vampires are mythological or folkloric beings who subsist by feeding on the life essence of living creatures, regardless of whether they are undead or a living person...
  
  s in folklore and many fictional stories (including Buffy the Vampire Slayer and Anne Rice
  Anne Rice
  Anne Rice is a best-selling Southern American author of metaphysical gothic fiction, Christian literature and erotica from New Orleans, Louisiana. Her books have sold nearly 100 million copies, making her one of the most widely read authors in modern history...
  
  's Vampire Chronicles
  The Vampire Chronicles
  The Vampire Chronicles is a series of novels by Anne Rice that revolves around the fictional character Lestat de Lioncourt, a French nobleman turned into a vampire in the 18th century....
  
  ) increase their number by converting or "siring" humans into their own kind. This usually involves blood exchange between the vampire and the victim, and can be forced or voluntary. Many works of fiction extend this to lycanthropy as well.
• Zombie
  Zombie
  Zombie is a term used to denote an animated corpse brought back to life by mystical means such as witchcraft. The term is often figuratively applied to describe a hypnotized person bereft of consciousness and self-awareness, yet ambulant and able to respond to surrounding stimuli...
  
  s appear in many horror films and stories (including Night of the Living Dead
  Night of the Living Dead
  Night of the Living Dead is a 1968 American independent black-and-white zombie film and cult film directed by George A. Romero, starring Duane Jones, Judith O'Dea and Karl Hardman. It premiered on October 1, 1968, and was completed on a USD$114,000 budget. After decades of cinematic re-releases, it...
  
  ) and often increase their numbers through biting people. If the person is not killed, they will die within hours and rise up as a zombie themselves. Zombies usually do not consciously try to increase their number, however, as they seek to consume their victims. Thus, only those that are bitten and get away from or destroy the zombie that bit them are in danger of becoming a zombie, rather than a zombie meal.