| Name | Source | Type |
|---|
| Cabal | Destiny franchise | Large, rhinoceros-like humanoids from the planet of Torobatl. Their politics and society are similar to that of Ancient Rome. |
| Caged dude | | |
| | Feline humanoid |
| Star Wars | |
| Caleban | Frank Herbert's Whipping Star | invisible telepathic beings who are actually the minds of stars |
| | |
| Callineans | Star Fleet | Humanoid |
| Calvin | Life | | Cephalopod-like |
| | |
| Campbellians | ChÅdenji Robo Combattler V | |
| Canaria | | |
| Capelons | Ascendancy | |
| Conductoid | Ben 10 | Black-skinned aliens from planet Teslavorr, Conductoids are cycloptic humanoids with plugs on their fingers, prehensile tail, and antenna on their heads. They have the ability to absorb energy and redirect it as electrical energy. |
| Cascan | Ben 10 | Hailing from planet Cascareau in the Andromeda Galaxy, these aliens are very similar to Orishans, being armored humanoids able to manipulate water. |
| Star Trek | Reptilian Humanoid |
| Carggites | DC Comics | A humanoid species from the planet Cargg who can split into three bodies at will. The Legion of Super-Heroes member Luornu Durgo is a Carggite. |
| Doctor Who | Humanoid |
| Red Dwarf | Felis Sapiens. Evolved over the course of three million years in deep space, from a domesticated housecat. |
| Bravest Warriors | A combination part cat and part ladybug, Catbug simultaneously exists in two dimensions; reality and the See-Through Zone. |
| Star Wars | Cat-like humanoid |
| Doctor Who | Feline Humanoid. |
| Cat People | The Garfield Show | Feline humanoid. |
| | Feline humanoid |
| Catalyte | Utopia | |
| | |
| Cavalier | Tommy & PJ | |
| Cazare | Ratchet & Clank | |
| Celareon | | |
| Celatid | | |
| Marvel Comics | |
| Celestialsapien | Ben 10 | Horned humanoids with a body similar to that of a starry night sky from the Forge of Creation, they can warp space, time and reality. However, they are limited by their psyche: their minds are divided into separate personalities that need to agree to do even simple tasks, causing them to remain motionless for long periods of time. |
| Babylon 5 | Humanoid |
| Centrans | Christopher Anvil's Pandora's Planet stories | Feline humanoids |
| Cerebrocrustacean | Ben 10 | Crab-like aliens from the planet Encephalonus IV. They are extremely intelligent and can generate electricity. |
| Ceti eel | | bug-like brain parasites from Ceti Alpha V |
| Chaethe | Kathy Tyers's One Mind's Eye | |
| Chalnoth | Star Trek | |
| Chamachies | Ascendancy | |
| Star Trek | |
| Chaos | Independence War | |
| Charrids | Farscape | Humanoid |
| Chasch | Jack Vance's Planet of Adventure Series | Big headed humanoids divided in subspecies. |
| Chatilian | Battlelords of the 23rd Century | Humanoid |
| Cheblons | | |
| Dragon's Egg | inhabitants of neutron star |
| Chelonians | Doctor Who novels | |
| Star Control | Crystalline life-form |
| Cherubs | Homestuck | Cherubs are characterized by their green exoskeleton. |
| Chevanno | Utopia | |
| Chevin | Star Wars | Amebelodontidae alien race |
| C. J. Cherryh's Chanur novels | |
| | |
| | Reptilian Hybrids between virus and host |
| Chimera Sui Generis | Ben 10 | Green-skinned cephalopodic humanoids from the planet Vilgaxia. |
| Chinger | Bill, the Galactic Hero | |
| Star Wars | Blue-skinned red-eyed humanoids |
| Star Control | |
| Cho-choi | Jack McDevitt's Infinity Beach | |
| | Universe devourers |
| | Bird-like species. Extremely technologically advanced and spread out across the galaxy. |
| Chronian | | A humanoid species who can manipulate time. |
| Chronomyst | Ascendancy | |
| | |
| Cinnrusskin | James White's Sector General series | |
| Cirronians | | |
| Cizerack | Battlelords of the 23rd Century | |
| Clairconctlar | Star Control 3 | |
| Clutch Turtles | | |
| Cocytans | The Dig | Furry, bird-like beings trapped in "Spacetime Six", a parallel universe. |
| | Similar to a big cat; prehensile tentacles sprouting from shoulders. Feeds on potassium and/or organic phosphorus. |
| Cognocenti | Star Trek | |
| Colatas | Farscape | Humanoid |
| Cole | | |
| Cole | Tracker | |
| The X-Files | |
| Colour out of space | | |
| Coluans | DC Comics | A humanoid species with green skin and vast intelligence. The supervillain Brainiac and his family are Coluans. |
| Half-Life 2 | An alien empire. Many of the "Combine" seen in the game are humans who have been assimilated or collaborate as brutal police troopers. |
| Saturday Night Live | Humanoid with conical heads |
| Control Brains | Invader Zim | The Control Brains assign the Irken race with roles and are the unspoken leaders of the Irken Empire. |
| Coreeshi | Farscape | Humanoid |
| Coridanite | Star Trek | Humanoid |
| Corporal Giroro | Sgt. Frog | |
| Corvallen | Star Trek | Reptilian Humanoid |
| Halo | Collective of alien species who are allied with each other, Composed of Grunts, Brutes, Elites, Hunters, Jackals, and Prophets. Religious Hierarchy with intent to destroy the Human Race. |
| Crystals | Raiden | Hi-tech aliens that has control over red crystals with unlimited powers, which are used to power up their weapons and equipment. |
| Cragmite | Ratchet & Clank | |
| Creators | | |
| Crescendolls | Interstella 5555 | An alien band, inspired by the Daft Punk song of the same name. |
| Crites | Critters films | carnivorous hairballs |
| Cryons | Doctor Who | A crystalline humanoid race from planet Telos, they cannot survive temperatures above the freezing point, boiling and steaming in said temperatures. |
| Ctarl-Ctarl | Outlaw Star | |
| | |
| Cuber | Adventure Time | |
| Doctor Who | Marauding cybernetic life-forms. Originally an alien race driven to conversion by catastrophic climate change, more recently reimagined as assimilated humans. |
| Cybertronians | Transformers | Large robots from planet Cybertron able to change their shape at will into other mechanical constructs, most commonly varying types of vehicles like planes and trucks. Known more commonly as Transformers. |
| Cybyota | Orion's Arm | |
| Cyclons | | |
| Battlestar Galactica | Sentient robots. Remnants of a civilization of reptilian aliens (also known as Cylons) in the original series, but created by humans in the remake series. Both mechanical and biological flesh-and-blood versions co-exist, with the biological versions in charge. |
| Cynoid | Master of Orion III | |
| Cyrollan | The Journeyman Project | | |
