List of fictional alien species: P

Name	Source	Type
Paan'uri	Schlock Mercenary	Dark matter entities
Pah Wraith	Star Trek
Pak, aka Protectors	Larry Niven's Known Space books	Humanoid, with three distinct life stages. First stage: Child, Second Stage: Breeder (known on earth as Homo Erectus), Third Stage: Protector, (superintelligent, could not survive on Earth).
Pakled	Star Trek
Parillatians	Utopia
Pascalenes	Utopia
Pascians	Battlelords of the 23rd Century
Pas'utu'ril	Orion's Arm	Six-legged aliens hailing from a large ringed planet outside the Terragen Sphere. Communicate through changing color patterns on their skin.
Pemalites	K. A. Applegate's Animorphs	Dog-like aliens, extremely friendly
Pentapods	2300 AD
The People from the Home	Ingathering: The Complete People Stories by Zenna Henderson	Very like Earth people, but have paranormal powers. Some came to live in small communities on Earth, after their own planet, "the Home", was destroyed.
Pequeninos	Orson Scott Card's Speaker for the Dead
Perry the Living Island of Insight	Adventure Time: Fionna and Cake
Petrosapien	Ben 10	A race of silicon-based aliens, they mostly resemble humanoids made out of pale-green/blue crystals. They hail from the planet Petropia, and are able to manipulate crystal to a great extent, and can also shapeshift their bodies so as to form sharp blades out of their bodies. However, they were almost totally extinct for most of the original series, owing to a young Tetrax Shard betraying his people and handing the galactic warlord Vilgax a sacred crystal that he used to destroy Petropia. However, in "The Secret of Chromastone" in Ben 10: Alien Force, it is revealed that the crystal Tetrax stole was a backup for the entire planet and its people, and he and Ben managed to restore the planet and resurrect the Petrosapien race.
Pfhor	Marathon Trilogy
Pfifltrig	C. S. Lewis' Ransom Trilogy
Phagors	Brian W. Aldiss's Heliconia series	Humanoid
Phalanx	Marvel Comics
Phentari	Battlelords of the 23rd Century
Phibians	Dune universe
Phleebhutinskis	Space Quest
Phosphorescent Maze Midgets	Bravest Warriors	Midgets who live in the Lavarynth
Phtagurs	Metabarons
Pierson's Puppeteers	Larry Niven's Ringworld and Known Space series	Three legs, armless, two manipulative heads, brain in torso. Evolved from herbivorous herd animals. Most technologically advanced species in Known Space.
Pilots	Farscape	Crustaceanoid
Pinkunz	Space Quest
Pisciss Premanns	Ben 10	Little is known about what they truly look like, as the only confirmed individual of this species, the bounty hunter Kraab, had 95% of his body replaced with cybernetics due to injuries sustained in a war between his home planet Piscciss and the Pyronite home star Pyros. However, it can be assumed that Kraab built his mechanical body to resemble his original organic one, indicating that Premann resemble large Earth crabs with humanoid features.
Pisciss Volann	Ben 10	Fish-like aliens from the oceanic planet Piscciss, they are similar to several Earth marine creatures, such as alligators, sharks, and anglerfish. That have a luminescent dangle, the ability to withstand increased amounts of pressure, and the ability to swim at great speeds by combining their legs into a tail, making them resemble a merman. They are also voracious eaters, able to unhinge their jaws to bite into much larger objects and even rip through steel.
Pkunk	Star Control	Toucan or dodo-like
Planet Duo people	Let's Shake It	Humanoid
Planet Jackers	Invader Zim	The Planet Jackers' planet orbits a dying sun, so to keep it alive, they steal planets and hurl them into the sun to keep it burning.
Plerkappi	Harry Turtledove's Worldwar series	An aquatic animal native to Home and another delicacy by the Race.
P'lod	Weekly World News
Plookesians	Invader Zim	A peaceful race. Most notable of the Plookesians are Mooshy and Spoopty.
Plorgonarians	Lilo & Stitch	One-eyed, two-tongued, three-legged, squid-like creatures with green skin, narrow bodies, three fingers on each hand, and an antenna on top of their heads that functions as both a nose and an ear, and turns orange as they age. Their home planet, Plorgonar, resembles the head of a Plorgonarian when seen from space.
Ploxis	Star Control 3
Plutonians	Aqua Teen Hunger Force
Pnume	Jack Vance's Planet of Adventure series	Insectoid
Polionation Tech	Sims 2
Polymorph	Red Dwarf
Porquinhos	Orson Scott Card's Speaker for the Dead	Humanoid
Posleen	John Ringo's Legacy of the Aldenata
Prʔ*tanss	The High Crusade
Prawns	District 9
Precursors	Halo	Highly advanced, 15 meter tall, eurypterid beings
Predator aliens	Predator movie series
Primes	Peter F. Hamilton's Commonwealth Saga
The Prin	Sir Arthur Conan Doyle's The Lost World	Humanoids with red skin and highly advanced technology with a weakness to Earth's atmosphere
Prince	Vampire Idol	Vampire-humanoids
Princess Zip	Adventure Time
Private Tamama	Sgt. Frog
Progenitors	David Brin's Uplift Universe
Promethians	Rifts role-playing game	Humanoid; formidable ancient race of mysterious origin; reside primarily on Phase World, center of the Three Galaxies; possess "phase" powers, enabling manipulation of physical and dimensional space; generally indifferent to anything that does not pose a threat to themselves or the cosmos as a whole.
Prophets (San 'Shyuum)	Halo
Prophets	Star Trek
Proteans	AdventureQuest	Morphing metallic blobs
Protheans	Mass Effect
Protoculture	Macross series
Protoss	StarCraft	The Protoss are depicted as a physically strong sapient humanoid species with access to advanced psionic abilities.
Prypiatosian-B	Ben 10	A particular radioactive alien species who have to wear a heavy and bulky furnace-like armour, which is almost indestructible, to protect external life from themselves. They come form the planet Prypiatos in the Andromeda Galaxy, and have the ability to create and manipulate heat rays, with the ability of overheat their armour. Outside of it, they can fly at very high speeds and absorb huge amounts of energy, even from nuclear reactors.
Psilons	Master of Orion
Psions	Destiny franchise	Thinly-framed humanoid cyclopes with psionic abilities. Were once a slave race to the Cabal empire, but are now seen as equal.
Psirens	Red Dwarf	Shape-changing GELFs
Psychlos	Battlefield Earth	Humanoid
Psychons	Space: 1999	Humanoid with metamorphosis abilities, capable of "molecular transformation" into the form of organic material such as an animal or plant by knowing its molecular structure. This form can only be held for one hour, and they cannot change directly from one form to another.
The Puppet Masters	Robert A. Heinlein book of the same name
Purple Aliens	It's Walky!
Pyrians	Gene Roddenberry's Andromeda	Methane-breathing squid-like race
Pyronite	Ben 10	Magma-based humanoids from the star Pyros, who possess pyrokinetic (fire manipulation) abilities and are immune to high levels of heat. Since they have little contact with other species, they spend their whole lives perfecting their abilities, further detailed in the reboot series as engagement in extreme sports like windsurfing and dune buggy racing.
Pyroviles	Doctor Who	Humanoid rock-like aliens from Pyrovilia resembling golems in the form of Roman soldiers wearing Corinthian helmets. They are capable of converting humans into more of themselves much like an infection. Some of them appeared in Pompeii around the time of Mount Vesuvius' eruption in an attempt to repopulate Earth, only to be foiled by the Doctor.
Python Lizards	Battlelords of the 23rd Century