This is a list of fictional alien species from the science fiction

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...

 series 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...

, in alphabetical order. Major species are in bold.

It is notable that some of these species are sentient life forms, while others are alien "animals;" many (particularly those of Visser Three

Visser Three

Visser Three, born as Esplin 9466 Primary and later known as Visser One, is a fictional character and the main antagonist of the sci-fi book series Animorphs, written by K.A. Applegate. He is the leader of the Yeerk forces on Earth, having inherited the planet from Edriss 562, who was Visser One at...

's morphs) are never definitively classified in the books.

A

• Anati: Little is known of the Anati or their world; apparently a fleet of Yeerk ships disappeared around this planet, and Visser One
  Edriss 562
  Edriss 562 is a Yeerk that controls Marco's mother Eva. For most of the series, her rank is Visser One. She is the subject of the novel Visser, which describes her rise to and dramatic fall from power...
  
   was charged with overseeing the infestation of whatever race(s) lived there, with the punishment of death if she failed. Later on Taylor implies that the Anati situation has been badly handled, and indeed, Visser One's execution seems to indicate she failed.
• Andalite
  Andalite
  The Andalites are a fictional alien race of grazers in the Scholastic book series Animorphs.-Biology:The Andalites are fictional aliens from the book series and TV series Animorphs....
  
  
• Antarean Bogg: the first creature Visser Three
  Visser Three
  Visser Three, born as Esplin 9466 Primary and later known as Visser One, is a fictional character and the main antagonist of the sci-fi book series Animorphs, written by K.A. Applegate. He is the leader of the Yeerk forces on Earth, having inherited the planet from Edriss 562, who was Visser One at...
  
   was seen morphing into in The Invasion
  The Invasion (Animorphs)
  The Invasion, published in 1996 and written by K. A. Applegate, is the first book in the Animorphs series. It is narrated by Jake.-Plot summary:...
  
  , and the one with which he kills and eats Elfangor
  Elfangor-Sirinial-Shamtul
  Elfangor-Sirinial-Shamtul is a character in K. A. Applegate's book series Animorphs. He is of an alien race known as the Andalites. His adventures are highlighted in the book called The Andalite Chronicles, which takes place before the main Animorphs series.Elfangor is an Andalite war-prince, who...
  
  . It is a hulking, two-legged creature with an impossibly bloated head, arm-length teeth, merged features, and thick tentacles for arms. The Antarean Bogg was genetically engineered by the Arn
  Arn (Animorphs)
  The Arn are fictional creatures from the Animorphs book series. The Arns' physiology somewhat resembles that of birds . It is possible that the Arn were the galaxy's masters of biological innovation. Interestingly, this race created an entire ecosystem after an asteroid destroyed much of the life...
  
  .
• Arn
  Arn (Animorphs)
  The Arn are fictional creatures from the Animorphs book series. The Arns' physiology somewhat resembles that of birds . It is possible that the Arn were the galaxy's masters of biological innovation. Interestingly, this race created an entire ecosystem after an asteroid destroyed much of the life...
  
  

B

• B'heeon: Appears only in Alternamorphs #1: The First Journey
  The First Journey (Alternamorphs)
  Alternamorphs #1: The First Journey is the first book of the Alternamorphs series, a spinoff of the Animorphs series. It involves a second-person narrative so as to allow the reader to actually take part in the story...
  
  . Ax sees and identifies it in the jungle during the false-timeline Sario Rip. The B'heeon has a three-foot-wide sticky pink tongue. It turns out that this is a morph that Visser Three has. Due to this book being non-canon and written by a ghostwriter, it is doubtful that a "B'heeon" actually exists in the Animorphs universe.
• Bievilerd: A creature from the planet Ondar. It is described as almost being a living stealth bomber, completely jet black, with several large wings and a huge mouth.
• Breet: ?? (list appearance and brief description)

C

• Capasin
  Capasin
  The Capasins are a fictional race from the Animorphs book series first seen in The Ellimist Chronicles. They resemble squids, with giant, bulbous heads dominated by glittering blue eyes, a beak-like mouth, and a number of thin, multi-jointed arms. They came across images of the Ketran Games and...
  
  
• Chadoo: small, tree-dwelling creatures of the Hork-Bajir
  Hork-Bajir
  The Hork-Bajir are a race of aliens in the Animorphs novels.The Hork-Bajir are fictional aliens that are usually about seven feet tall. They are a dark shade of green and have three-toed theropod feet. Their necks are long and they have a mouth that resembles a falcon's beak with teeth. Their legs...
  
   home-world. They are featured in the book The Hork-Bajir Chronicles
  The Hork-Bajir Chronicles
  The Hork-Bajir Chronicles is the second companion book to the Animorphs series, written by K. A. Applegate. With respect to continuity within the series, it takes place before book #23, The Pretender, although the events told in the story occur between the time of The Ellimist Chronicles and The...
  
  . They have two elongated arms, four stubby legs, skin flaps, are covered in feathers and are very quick and agile. It is Aldrea
  Aldrea
  Aldrea-Iskillion-Falan is a fictional character in the Animorphs series.Aldrea is the daughter of Prince Seerow, a main character in Animorphs 34: The Prophecy and the heroine in The Hork-Bajir Chronicles...
  
  's second morph. Tree sap attracts them.

The Arn

Arn (Animorphs)

The Arn are fictional creatures from the Animorphs book series. The Arns' physiology somewhat resembles that of birds . It is possible that the Arn were the galaxy's masters of biological innovation. Interestingly, this race created an entire ecosystem after an asteroid destroyed much of the life...

 are possibly related to them (when Dak Hamee decided that they were large, colourful Arns, Aldrea

Aldrea

Aldrea-Iskillion-Falan is a fictional character in the Animorphs series.Aldrea is the daughter of Prince Seerow, a main character in Animorphs 34: The Prophecy and the heroine in The Hork-Bajir Chronicles...

 contradicted that they were just distant relatives).

• Chan Wath: minor species mentioned only in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  .
• Chee
  Chee
  The Chee are a fictional race of androids created by the extinct Pemalites, a race of pacifists from the sci-fi book series Animorphs, written by K. A. Applegate. The word Chee means "Friend" in the Pemalite language.-Fictional history:...
  
  

D

• Daankin
• Dayang: They are a fairly unknown race of people. At least some of them are traders, and one of them found a Pemalite Crystal
  Chee
  The Chee are a fictional race of androids created by the extinct Pemalites, a race of pacifists from the sci-fi book series Animorphs, written by K. A. Applegate. The word Chee means "Friend" in the Pemalite language.-Fictional history:...
  
  , though he did not know what it really was, and traded it to the Yeerks.
• Desbadeen: Only a couple minor mentions of this race are given in The Illusion
  The Illusion (Animorphs)
  The Illusion is the thirty-third book in the Animorphs series, written by K.A. Applegate. It is known to have been ghostwritten by Ellen Geroux. It is narrated by Tobias.-Plot summary:...
  
  , where Tobias has a flashback of Elfangor
  Elfangor-Sirinial-Shamtul
  Elfangor-Sirinial-Shamtul is a character in K. A. Applegate's book series Animorphs. He is of an alien race known as the Andalites. His adventures are highlighted in the book called The Andalite Chronicles, which takes place before the main Animorphs series.Elfangor is an Andalite war-prince, who...
  
  's memories of a space battle, when Elfangor remembers seeing "a Desbadeen tanker in the distinctive figure eight design" on the view screen, and in Visser, when Visser One compares Visser Three's host body to "that of an Earth deer or horse, or a Desbadeen limner".
• Djabala: small, six-legged creatures of the Andalite
  Andalite
  The Andalites are a fictional alien race of grazers in the Scholastic book series Animorphs.-Biology:The Andalites are fictional aliens from the book series and TV series Animorphs....
  
   home-world. They have a rather simple physiology, and similar enough to Andalites' so that the djabala is the first creature that arisths (lowest rank) morph during basic training.
• Dule Fansa: Visser Three morphs it in The Discovery
  The Discovery (Animorphs)
  The Discovery is the twentieth book in the Animorphs series, written by K.A. Applegate. It is narrated by Marco. It is the first book in the David trilogy.-Plot summary:...
  
  . Marco describes it as looking like a skinnier, more muscular version of Barney the Dinosaur, with a face located where most species' chests are. It has the ability to fire orange cones from its four arms, which can cause mass damage. He is first seen morphing it in David's room.

E

• Ellimist: The Ellimist is a creature that Ax says is all-powerful. He say he can make entire worlds disappear.

  The 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...

  
   first meet him in book 7 The Stranger

  The Stranger (Animorphs)

  The Stranger is the seventh book in the Animorphs series, written by K.A. Applegate. It is narrated by Rachel.-Plot summary:Rachel's father asks her to move with him to another state. After some reconnaissance work, Marco and Tobias find an entrance to the underground Yeerk Pool, in one of the...

  
   just as they are about to be swallowed by a Taxxon.

  He then appears again in 13 The Change

  The Change (Animorphs)

  The Change is the thirteenth book in the Animorphs series, written by K.A. Applegate. It is narrated by Tobias.-Plot summary:Tobias takes Rachel on a tour, to show her the Yeerk pool entrance that he had discovered. Soon, though, he finds he is not where he was heading; they suddenly are flying...

  
   where he gives Tobias

  Tobias

  Tobias is a Greek version of the Hebrew biblical name "Toviyah" , meaning "Yahweh is good". It is a popular male given name in Germany, Scandinavia, the United States and amongst Jewish people. In English-speaking countries it is often shortened to Toby. Other diminutives are Tobi , Tobsen and...

  
   his morphing power back. He appears other time through the series as well, including 26 The Attack

  The Attack (Animorphs)

  The Attack is the twenty-sixth book in the Animorphs series, written by K.A. Applegate. It is narrated by Jake.-Plot summary:...

  
   and uses them to fight The Howlers.

• endrid

F

• The Five: hunted the Venber to extinction, using the Venbers' melted forms as computer superconductors. After an encounter with the Andalite
  Andalite
  The Andalites are a fictional alien race of grazers in the Scholastic book series Animorphs.-Biology:The Andalites are fictional aliens from the book series and TV series Animorphs....
  
  s, the Five themselves disappeared completely.
• Folk: mentioned briefly in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  as a eugenic species that kills up to ninety percent of its own children. During a challenge set up by Crayak
  Crayak
  Crayak is a fictional character and villain from the science-fiction book series Animorphs, written by K. A. Applegate.-Description:Crayak is a nearly omnipotent entity appearing in the form of an armless cyborg with massive limbs and nothing but what would resemble as a blood-red eye for a head...
  
  , the Ellimist
  Ellimist
  The Ellimist is a fictional character from the science fiction novel series Animorphs.The Ellimist is an almost god-like being, displaying many reality warping powers, though it is stated several times that while he appears to be, he is not omnipotent. By standard values, the Ellimist is a force of...
  
   fails to save their planet from an asteroid, which destabilized the planet's orbit until it fell into their sun's gravity well
  Gravity well
  A gravity well or gravitational well is a conceptual model of the gravitational field surrounding a body in space. The more massive the body the deeper and more extensive the gravity well associated with it. The Sun has a far-reaching and deep gravity well. Asteroids and small moons have much...
  
  .
• Fire Creature: Visser Three's second morph, seen near the end of the first book. A creature of immense size, it has 8 legs, 8 arms, and 8 heads, each with a mouth that can launch fireballs. This creature is so fearsome, even taxxons withdraw from Visser Three when he becomes it. No actual name is given for this creature, but the Visser kindly states he got it from "the 4th moon of the 2nd planet of a dying star."

G

• Galilash: A species native to the Hork-Bajir homeworld, created by the Arn
  Arn (Animorphs)
  The Arn are fictional creatures from the Animorphs book series. The Arns' physiology somewhat resembles that of birds . It is possible that the Arn were the galaxy's masters of biological innovation. Interestingly, this race created an entire ecosystem after an asteroid destroyed much of the life...
  
   to prevent Hork-Bajir
  Hork-Bajir
  The Hork-Bajir are a race of aliens in the Animorphs novels.The Hork-Bajir are fictional aliens that are usually about seven feet tall. They are a dark shade of green and have three-toed theropod feet. Their necks are long and they have a mouth that resembles a falcon's beak with teeth. Their legs...
  
   from crossing the zone of separation. The Galilish, are fourteen feet tall, with green and red reptilian flesh and razored tentacles.
• Garatron: similar in appearance to the (presumably) unrelated Andalite
  Andalite
  The Andalites are a fictional alien race of grazers in the Scholastic book series Animorphs.-Biology:The Andalites are fictional aliens from the book series and TV series Animorphs....
  
  s, with a few differences, such as lacking stalk eyes or a tail blade. They are also capable of instantaneously fast movement that far surpasses the speed of just about any Earth animal. They use a form of thought speech that is very fast and condensed compared to the standard form of thought speak, lacking any pauses between words or punctuation. They are capable of running on water as seen in #37: The Weakness
  The Weakness (Animorphs)
  The Weakness is the thirty-seventh book in the Animorphs series, written by K.A. Applegate. It is known to have been ghostwritten by Elise Smith...
  
  when a Garatron-Controller ran across the surface of a Yeerk Pool. The Garatron-Controller was killed by Marco
  Marco (Animorphs)
  Marco is a fictional character from the sci-fi book series, Animorphs, written by K. A. Applegate. His last name is never mentioned.-Biography:...
  
   in cobra morph, when he bit and poisoned the Garatron. The poisoned Garatron was surprised by the speed of the cobra. It is possible that the Garatron has an advanced metabolism that allowed the poison to spread more quickly than it would in a human.
• Gedd
  Gedd
  Gedds are a species of aliens in the Animorphs book series. They evolved on the same planet as the Yeerks. The Gedds are a primate-like species, with terrible vision and bad motor skills. They served as the first hosts for the parasitic Yeerks....
  
  s
• Generationals: mentioned only in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  as being a "corporate life form" the Ketran
  Ketran
  The Ketrans are a fictional race from the Animorphs book series; they lived in giant crystals hovering above a lava-covered planet. The Ellimist was once a member of this race, apparently one of the first technologically advanced sentient life-forms of the galaxy...
  
  s were familiar with. Each generation of theirs is numbered. (e.g. Generation 9561)
• Gofinickilast: a species mentioned in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  .
• Gork: A species native to the Hork-Bajir homeworld, created by the Arn to prevent Hork-Bajir from crossing the zone of separation. The Gork are described as being, three feet tall, but twenty feet across, they shuffle on twelve legs with snapping, extending mouths on all sides.
• Graffen's Children: They resemble Gumby
  Gumby
  Gumby is a green clay humanoid character created and modeled by Art Clokey, who also created Davey and Goliath. Gumby has been the subject of a 233-episode series of American television as well as a feature-length film and other media...
  
  , and are very peaceful. They were wiped out by the Howlers
  Howler (Animorphs)
  Howlers, or Crayak's Children, are the alien shock troops of the nearly omnipotent Crayak, in the sci-fi book series Animorphs.-Biology:...
  
  .
• Grasper: a species mentioned in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  .

H

• Hawjabran: Members of this species also have the unusual characteristic of having a brain that is not centralized in one place, as the human brain is centered in the head; theirs is spread in bits throughout their bodies, which makes them useless as hosts to the Yeerk
  Yeerk
  Yeerks are a fictional extraterrestrial species from the book and television series "Animorphs" written by K. A. Applegate and published by Scholastic.-Biology:...
  
  s. Early on, the Yeerks who escaped from their homeworld attacked a Hawjabran ship and, finding them useless, allowed all six thousand inhabitants to die from a lack of life-support systems. Their freighters
  Cargo ship
  A cargo ship or freighter is any sort of ship or vessel that carries cargo, goods, and materials from one port to another. Thousands of cargo carriers ply the world's seas and oceans each year; they handle the bulk of international trade...
  
   resemble the star-ship Enterprise from 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...
  
  , according to Aximili-Esgarrouth-Isthill
  Aximili-Esgarrouth-Isthill
  Aximili-Esgarrouth-Isthill is a fictional character from the sci-fi book series Animorphs.-Biography:Aximili is a young Andalite who becomes stranded on Earth when the Andalite Dome Ship GalaxyTree is shot down by Yeerk fighters...
  
   (Ax).
• Hayati: a species mentioned in The Ellimist Chronicles.
• Helmacron
  Helmacron
  The Helmacrons are a fictional race of aliens in the Animorphs universe. They are about a sixteenth of an inch tall with humanoid bodies with another set of legs. Their heads are perfectly flat on top, with large green eyes sitting on them. Their faces come down from the top in an inverted pyramid...
  
  
• Hoober: Small ground creatures from the Andalite
  Andalite
  The Andalites are a fictional alien race of grazers in the Scholastic book series Animorphs.-Biology:The Andalites are fictional aliens from the book series and TV series Animorphs....
  
   Homeworld that jump on tendrils and have bulging eyes.
• Hork-Bajir
  Hork-Bajir
  The Hork-Bajir are a race of aliens in the Animorphs novels.The Hork-Bajir are fictional aliens that are usually about seven feet tall. They are a dark shade of green and have three-toed theropod feet. Their necks are long and they have a mouth that resembles a falcon's beak with teeth. Their legs...
  
  
• Howler
  Howler (Animorphs)
  Howlers, or Crayak's Children, are the alien shock troops of the nearly omnipotent Crayak, in the sci-fi book series Animorphs.-Biology:...
  
  

I

• Illaman: mentioned in The Ellimist Chronicles as a species known to the Ketran
  Ketran
  The Ketrans are a fictional race from the Animorphs book series; they lived in giant crystals hovering above a lava-covered planet. The Ellimist was once a member of this race, apparently one of the first technologically advanced sentient life-forms of the galaxy...
  
  s.
• Inner Worlders: a species of winged, multiple-eyed aliens that are in a long-standing conflict with the Jallians.
• Iskoort
  Iskoort
  The Iskoort are a fictional race of aliens from the Animorphs series by K.A. Applegate.They are made up of two parts - an "Isk" and a "Yoort". The Isk is the main physical body, and the Yoort is a slug which must leave the Isk every three days to soak up kandrona rays...
  
  

J

• Jallian: a species of slug-like, multi-armed aliens in a long-standing conflict with the Inner Worlders. Their entire species is eventually destroyed by the Inner Worlders.
• Jubba-Jubba: A species native to the Hork-Bajir homeworld, created by the Arn
  Arn (Animorphs)
  The Arn are fictional creatures from the Animorphs book series. The Arns' physiology somewhat resembles that of birds . It is possible that the Arn were the galaxy's masters of biological innovation. Interestingly, this race created an entire ecosystem after an asteroid destroyed much of the life...
  
   to prevent Hork-Bajir
  Hork-Bajir
  The Hork-Bajir are a race of aliens in the Animorphs novels.The Hork-Bajir are fictional aliens that are usually about seven feet tall. They are a dark shade of green and have three-toed theropod feet. Their necks are long and they have a mouth that resembles a falcon's beak with teeth. Their legs...
  
   from crossing the zone of separation. Large and terrifyingly strong, three fingered creatures, the jubba-jubba are capable of pulling limbs from bodies with complete ease.

K

• Kafit Bird: Andalite homeworld. There are only three species of bird, and the kafit is considered the best, with six powerful wings and a razor bill for a beak. In the early days of the Yeerk
  Yeerk
  Yeerks are a fictional extraterrestrial species from the book and television series "Animorphs" written by K. A. Applegate and published by Scholastic.-Biology:...
  
  -Andalite war, training arisths acquired the kafit and flew around for amusement.
• Kaftid: A creature from the Hork-Bajir
  Hork-Bajir
  The Hork-Bajir are a race of aliens in the Animorphs novels.The Hork-Bajir are fictional aliens that are usually about seven feet tall. They are a dark shade of green and have three-toed theropod feet. Their necks are long and they have a mouth that resembles a falcon's beak with teeth. Their legs...
  
   world, with eight legs, a seahorse-like head, slimy skin, and the ability to shoot acid.
• Kelbrid: aggressive yet trustworthy enemies of the Andalites mentioned only in The Beginning
  The Beginning (Animorphs)
  The Beginning is the fifty-fourth and final book in the Animorphs series. Unlike other Animorphs books in the main series, but similar to the Megamorphs, all characters conduct narration instead of just one.-Plot summary:...
  
  . Their powerful empire borders Andalite space, but neither side is allowed to interact with the territory of the other; as a result Andalites do not even know what the Kelbrid look like.
• Ketran
  Ketran
  The Ketrans are a fictional race from the Animorphs book series; they lived in giant crystals hovering above a lava-covered planet. The Ellimist was once a member of this race, apparently one of the first technologically advanced sentient life-forms of the galaxy...
  
  
• Korla: mentioned in Megamorphs #2: In the Time of Dinosaurs
  In the Time of Dinosaurs (Megamorphs)
  #2: In the Time of Dinosaurs is the second book in the series, a set of companion books to the Animorphs series. With respect to continuity, it takes place between book #18, The Decision and book #19, The Departure...
  
  by Ax, who implies that they are rather odd-looking, as the Taxxons and Skrit
  Skrit Na
  The Skrit Na are a race of aliens from the Animorphs book series by K.A. Applegate. They capture specimens from the many planets they visit and either perform strange medical procedures on them or put them in a zoo on their homeworld...
  
   are.

L

• Laga: a peaceful race mentioned only in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  . The Ellimist
  Ellimist
  The Ellimist is a fictional character from the science fiction novel series Animorphs.The Ellimist is an almost god-like being, displaying many reality warping powers, though it is stated several times that while he appears to be, he is not omnipotent. By standard values, the Ellimist is a force of...
  
   fails to save their planet from an asteroid sent by Crayak
  Crayak
  Crayak is a fictional character and villain from the science-fiction book series Animorphs, written by K. A. Applegate.-Description:Crayak is a nearly omnipotent entity appearing in the form of an armless cyborg with massive limbs and nothing but what would resemble as a blood-red eye for a head...
  
  .
• Lebtin Javelin Fish: a large yellow-coloured aquatic creature, with brightly coloured natural harpoons stored within its body. The colour of these harpoons is probably a means of camouflage on its home planet. (Book 12)
• Leeran
  Leeran
  The Leerans are a fictional race of aliens from the Animorphs series by K.A. Applegate. They are described as a yellow amphibian species with tentacles for arms that resembles a manta ray or frog...
  
  
• Lerdethak
  Lerdethak
  The Lerdethak is a fictional creature from the Animorphs book series, specifically Animorphs #11: The Forgotten and The Hork-Bajir Chronicles....
  
  
• Luminar: morphed by Visser Three in The Mutation
  The Mutation (Animorphs)
  The Mutation is the thirty-sixth book in the Animorphs series, written by K.A. Applegate. It is known to have been ghostwritten by Erica Bobone. It is narrated by Jake.-Plot summary:...
  
  , the Luminar is vaguely humanoid and capable of generating enough heat that it can burn its victims to ash from a few feet away. Unsurprisingly, it is incredibly vulnerable to water. Water does not seem to hurt it, though it does seem to lose its fire power while in water (temporarily).

M

• Mardrut: a whale-sized creature, dark red in color with tiny thrashing 'fish tails' all along its back, that lives on one of the moons orbiting the Andalite
  Andalite
  The Andalites are a fictional alien race of grazers in the Scholastic book series Animorphs.-Biology:The Andalites are fictional aliens from the book series and TV series Animorphs....
  
   home world. It moves by shooting water out of three huge water sacs. Visser Three has this creature as a morph, used in The Message
  The Message (Animorphs)
  The Message, published in 1996 and written by K.A. Applegate, is the fourth book in the Animorphs series. It is narrated by Cassie.-Plot summary:Cassie and Tobias are having strange dreams about a presence in the ocean...
  
  .
• Mak: Temrash 114 claimed that the Yeerk
  Yeerk
  Yeerks are a fictional extraterrestrial species from the book and television series "Animorphs" written by K. A. Applegate and published by Scholastic.-Biology:...
  
  s had conquered this species.
• Mamathisk: a species mentioned in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  .
• Mashtimee: a species mentioned in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  . Also mentioned in Animorphs 26 The Attack
  The Attack (Animorphs)
  The Attack is the twenty-sixth book in the Animorphs series, written by K.A. Applegate. It is narrated by Jake.-Plot summary:...
  
   as a species wiped out by the Howlers
  Howler (Animorphs)
  Howlers, or Crayak's Children, are the alien shock troops of the nearly omnipotent Crayak, in the sci-fi book series Animorphs.-Biology:...
  
  .
• Mercora
  Mercora (Animorphs)
  The Mercora are a fictional race of aliens in the Animorphs books by K.A. Applegate first seen in Megamorphs #2: In the Time of Dinosaurs. They resemble giant crabs with very asymmetrical bodies. On one side of the body is a large pincer and on the other are two human-like arms. They also had seven...
  
  
• Mortrons: Composed of two separate entities (a yellow and black bottom half with wheels, and a red elongated head with razor-sharp teeth and concealed wings), the Mortrons were a pet species of Esplin 9466
  Visser Three
  Visser Three, born as Esplin 9466 Primary and later known as Visser One, is a fictional character and the main antagonist of the sci-fi book series Animorphs, written by K.A. Applegate. He is the leader of the Yeerk forces on Earth, having inherited the planet from Edriss 562, who was Visser One at...
  
  . Mortrons are regenerative, meaning if one of them is cut in half, it will sprout into two full Mortrons.
• Multitudinal: a species mentioned in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  .

N

• Nahara: A species that have been completely enslaved by the Yeerk
  Yeerk
  Yeerks are a fictional extraterrestrial species from the book and television series "Animorphs" written by K. A. Applegate and published by Scholastic.-Biology:...
  
  s.
• Nartec
  Nartec
  The Nartec are a fictional terrestrial species appearing in the Animorphs series, that first appeared in Animorphs 36: The Mutation, narrated by Jake. They were possibly inspired by the legend of Atlantis. They are humanoids that live in a giant cave under the ocean off the coast of the Animorphs'...
  
  
• Nesk
  Nesk
  The Nesk are a race of aliens in the fictional Animorphs books by K.A. Applegate. They are actually made up of thousands of intelligent ants that join together to form into the shape of a body capable of using the technology they have stolen from other species. They lived on Earth 65 million...
  
  
• Norshk: at least some of them are space pirates, mentioned only in The Beginning
  The Beginning (Animorphs)
  The Beginning is the fifty-fourth and final book in the Animorphs series. Unlike other Animorphs books in the main series, but similar to the Megamorphs, all characters conduct narration instead of just one.-Plot summary:...
  
  .
• Nostnavay: a species mentioned in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  . Also mentioned in Animorphs 26 The Attack
  The Attack (Animorphs)
  The Attack is the twenty-sixth book in the Animorphs series, written by K.A. Applegate. It is narrated by Jake.-Plot summary:...
  
   as a species wiped out by the Howlers
  Howler (Animorphs)
  Howlers, or Crayak's Children, are the alien shock troops of the nearly omnipotent Crayak, in the sci-fi book series Animorphs.-Biology:...
  
  .

O

• Ongachic: Some of their race have been taken by the Yeerk
  Yeerk
  Yeerks are a fictional extraterrestrial species from the book and television series "Animorphs" written by K. A. Applegate and published by Scholastic.-Biology:...
  
  s, but they fled their homeworld long ago. Now they live all throughout the galaxy as a nomad
  Nomad
  Nomadic people , commonly known as itinerants in modern-day contexts, are communities of people who move from one place to another, rather than settling permanently in one location. There are an estimated 30-40 million nomads in the world. Many cultures have traditionally been nomadic, but...
  
  ic tribe, and as a result of their decentralization, only a few are known to be Controllers. While watching a 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...
  
  movie in book 8
  The Alien (Animorphs)
  The Alien is the eighth book in the Animorphs series, written by K. A. Applegate. It is the first book narrated by Ax.-Plot:...
  
   (either First Contact
  Star Trek: First Contact
  Star Trek: First Contact is the eighth feature film in the Star Trek science fiction franchise, released in November 1996, by Paramount Pictures. First Contact is the first film in the franchise to feature no cast members from the original Star Trek television series of the 1960s...
  
  or Insurrection
  Star Trek: Insurrection
  Star Trek: Insurrection is a 1998 American science fiction film directed by Jonathan Frakes, written by Michael Piller , and with music composed by Jerry Goldsmith. It is the ninth film in the Star Trek franchise, and the third to feature the cast from the television series Star Trek: The Next...
  
  ), Ax
  Aximili-Esgarrouth-Isthill
  Aximili-Esgarrouth-Isthill is a fictional character from the sci-fi book series Animorphs.-Biography:Aximili is a young Andalite who becomes stranded on Earth when the Andalite Dome Ship GalaxyTree is shot down by Yeerk fighters...
  
   once commented that a Klingon
  Klingon
  Klingons are a fictional warrior race in the Star Trek universe.Klingons are recurring villains in the 1960s television show Star Trek: The Original Series, and have appeared in all five spin-off series and eight feature films...
  
   - presumably Worf
  Worf
  Worf, played by Michael Dorn, is a main character in Star Trek: The Next Generation and in seasons four to seven of Star Trek: Deep Space Nine. He also appears in the films based on The Next Generation. Worf is the first Klingon main character to appear in Star Trek, and has appeared in more Star...
  
   - was "clearly an Ongachic female." In The Hork-Bajir Chronicles
  The Hork-Bajir Chronicles
  The Hork-Bajir Chronicles is the second companion book to the Animorphs series, written by K. A. Applegate. With respect to continuity within the series, it takes place before book #23, The Pretender, although the events told in the story occur between the time of The Ellimist Chronicles and The...
  
  , Esplin 9466
  Visser Three
  Visser Three, born as Esplin 9466 Primary and later known as Visser One, is a fictional character and the main antagonist of the sci-fi book series Animorphs, written by K.A. Applegate. He is the leader of the Yeerk forces on Earth, having inherited the planet from Edriss 562, who was Visser One at...
  
   comments that the Galard language was learned from Ongachic hosts, because the Yeerk language (clicks and ultrasonic squeaks) was impossible to speak with Gedd mouths. Galard became the common intergalactic language. Ongachic wave-particle technology was also combined with Andalite shredder technology to create the Dracon Beam.
• Orff
  Orff (Animorphs)
  The Orff are a fictional alien species in K. A. Applegate's young adult book series, Animorphs. They are described as being vaguely humanoid, with three quick legs and a long flexible neck ending in a single large internally lit eye The pupils of their eyes float freely about their eyes instead of...
  
  

P

• Pangaban: A species mentioned in The Ellimist Chronicles
  The Ellimist Chronicles
  The Ellimist Chronicles is a children's science-fiction novel, a companion book to the Animorphs series written by K. A. Applegate. It tells the backstory of the Ellimist, a god-like being from the story...
  
  
• Pemalite
  Pemalite
  The Pemalites are a fictional alien species from the Animorphs series by K.A. Applegate. In appearance they resemble dogs, though they walk on their hind legs.-Creation:...
  
  
• Pon: a species destroyed by the Howlers
  Howler (Animorphs)
  Howlers, or Crayak's Children, are the alien shock troops of the nearly omnipotent Crayak, in the sci-fi book series Animorphs.-Biology:...
  
  

S

• Sharf Den: a species that the Howlers
  Howler (Animorphs)
  Howlers, or Crayak's Children, are the alien shock troops of the nearly omnipotent Crayak, in the sci-fi book series Animorphs.-Biology:...
  
   will greet by attempting to kiss them.
• Skrit Na
  Skrit Na
  The Skrit Na are a race of aliens from the Animorphs book series by K.A. Applegate. They capture specimens from the many planets they visit and either perform strange medical procedures on them or put them in a zoo on their homeworld...
  
  
• Sstram: Temrash 114 claimed that the Yeerk
  Yeerk
  Yeerks are a fictional extraterrestrial species from the book and television series "Animorphs" written by K. A. Applegate and published by Scholastic.-Biology:...
  
  s had conquered this species.

U

• Unemite: They are non-spacefaring. Their appearance varies drastically among members of the species; face and hair colors vary, and the number of arms ranges from three to nine. They have two eyes facing forward, and one backward. They enjoy the music of the adge, an instrument with a mouthpiece and seven strings. In The Ellimist Chronicles, Skrit Na
  Skrit Na
  The Skrit Na are a race of aliens from the Animorphs book series by K.A. Applegate. They capture specimens from the many planets they visit and either perform strange medical procedures on them or put them in a zoo on their homeworld...
  
   captured a Unemite. They were eventually "merged" into "Father", who used music as a game to play against the Ellimist
  Ellimist
  The Ellimist is a fictional character from the science fiction novel series Animorphs.The Ellimist is an almost god-like being, displaying many reality warping powers, though it is stated several times that while he appears to be, he is not omnipotent. By standard values, the Ellimist is a force of...
  
  . The Unemite eventually became part of the Ellimist as he collected Father's minds.

V

• Vanarx: Also known as the Yeerkbane, they look like large, transparent purple bipeds with raptor-like bodies and a long tubelike head. They eat Yeerk
  Yeerk
  Yeerks are a fictional extraterrestrial species from the book and television series "Animorphs" written by K. A. Applegate and published by Scholastic.-Biology:...
  
  s by sucking the controller's head until the Yeerk comes out.
• Veleek
  Veleek
  The Veleek is a fictional alien creature from the Animorphs series of books. The creature resembles a cloud of dust but can form blades and teeth to attack its prey with. It isn't strictly one creature but millions of tiny beings acting as one...
  
  
• Venber: Venbers are a race of hydrogen-based aliens, about human size but much taller. They are silver with streaks of blood-red or midnight-blue on their shoulders, waist, and hammerhead shark-like head. Venbers have 4 arms, the lower two of which hold pole-like appendages. Venber live in very low temperature conditions, and because of their hydrogen-based constitution, when they reach temperatures above freezing, they melt. At one time, they lived on a freezing moon and were among the first alien species that the Andalite
  Andalite
  The Andalites are a fictional alien race of grazers in the Scholastic book series Animorphs.-Biology:The Andalites are fictional aliens from the book series and TV series Animorphs....
  
  s came in contact with, but they were wiped out by a race known as The Five who melted their bodies for superconductors, and who in turn were wiped out by the Andalites in retaliation. The Yeerks made a crossbreed of Human and Venber for use as biological robots in a secret facility in the Arctic
  Arctic
  The Arctic is a region located at the northern-most part of the Earth. The Arctic consists of the Arctic Ocean and parts of Canada, Russia, Greenland, the United States, Norway, Sweden, Finland, and Iceland. The Arctic region consists of a vast, ice-covered ocean, surrounded by treeless permafrost...
  
  ; using them as hosts would have been impractical because the Yeerks would freeze to death.Because of this, it cannot be decided which parts of the Venber are human.

Y

• Yamphut: A virus from the andalite homeworld. It can be fatal in andalites, causing the tria gland to burst. It is communicable to humans and causes flu-like symptoms in them.
• Yeerk
  Yeerk
  Yeerks are a fictional extraterrestrial species from the book and television series "Animorphs" written by K. A. Applegate and published by Scholastic.-Biology:...
  
  
• Yoort