->"He was a candidate for a Midwestern congressional seat, and he hired me to manage his campaign advertising. Unfortunately, his opponent turned up something in his past with which we could not cope."\\
"Let me guess: he was secretly a liberal."\\
"Worse. An alien."\\
"You're kidding?! An undocumented alien running for--"\\
"No. A space alien, Ms. Walters."
--> -- ''[[SheHulk Sensational She-Hulk]]'' #11, Jan. 1990

A character of extraterrestrial origins. For tropes about what ''makes'' them alien, see BizarreAlienBiology.

[[Film/{{Aliens}} If you thought it meant "illegal aliens" and signed up]], click RaceTropes. For interspecies romantic or sexual interactions, see the InterracialAndInterspeciesLoveIndex.

If there are no aliens at all, see AbsentAliens.

Not to be confused with OthernessTropes, though there may be some overlap.
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!!Tropes

Levels of the ladder of alien strangeness:[[index]]
* HumanAliens
* HumanSubspecies
** TranshumanAliens
* NotQuiteHuman
* RubberForeheadAliens
** GreenSkinnedSpaceBabe
** SpaceElves
* HumanoidAliens
** PettingZooPeople (sometimes they're aliens)
*** CatFolk
** LittleGreenMen
** TheGreys
** TheReptilians
* LittleGreenManInACan
* InsectoidAliens
* IntelligentGerbil
* MechanicalLifeforms
* AlienAnimals
** BlobMonster (amoeba)
** KillerSpaceMonkey
** SpaceWhale
** SandWorm (worms)
* BigCreepyCrawlies
* LowCultureHighTech
* PlantAliens
* StarfishAliens
** EldritchAbomination
* SiliconBasedLife
* EnergyBeings
* GeniusLoci
* SufficientlyAdvancedAlien
** InsufficientlyAdvancedAlien
* MechanisticAlienCulture

SFX:
* PeopleInRubberSuits
* {{Muppet}}
* SerkisFolk

General tropes:
* AlienAutopsy
* AlienInvasion
** BenevolentAlienInvasion
* AlternativeNumberSystem
* AnalProbing
* BrainInAJar
* DittoAliens
* TheDogIsAnAlien
* MistakenForAliens
* MyBrainIsBig
* {{Panspermia}}
* NoSuchThingAsAlienPopCulture
* PeopleJars
* PuppeteerParasite

Interspecies relations:
* AliensAreBastards
* AlienNonInterferenceClause
* AliensSpeakingEnglish
* AncientAstronauts
* {{Area 51}}
* DescriptivelyNamedSpecies
* FirstContact
* FirstContactMath
* FirstContactTeam
* HumansAreSmelly
* HumansNeedAliens
* IComeInPeace
** TakeMeToYourLeader
** WeComeInPeaceShootToKill
* InnocentAliens
* InscrutableAliens
* KlingonsLoveShakespeare
* MistookTheDominantLifeform
* ProtocolPeril
* TheRightOfASuperiorSpecies
* RoswellThatEndsWell
* ScaryDogmaticAliens
* ServantRace
* SlaveRace
* SuperiorSpecies
* ToServeMan
** JustForFun/HowToInvadeAnAlienPlanet
* WhatMeasureIsAHumanoid
* WhatMeasureIsANonHuman
* TheXenophile

Reproduction:
* DesignerBabies
* DyingRace
* ExoticEquipment
* FaceFullOfAlienWingWong
* ImmortalProcreationClause
* InterspeciesRomance
** BoldlyComing
** {{Gendercide}}
** HotSkittyOnWailordAction
** MarsNeedsWomen
** OnlyYouCanRepopulateMyRace
* PlanetaryParasite
* UterineReplicator

Genders:
* BizarreSexualDimorphism
* GenderEqualsBreed
* OneGenderRace

Other features:
* AbusiveAlienParents
* AlienAbduction
* AlienAmongUs
* AlienCatnip
* AlienKudzu
* AliensAndMonsters
* AliensNeverInventedTheWheel
* AliensStealCable
* AliensStealCattle
* APlanetNamedZok
* AmusingAlien
* BizarreAlienBiology
** BizarreAlienReproduction
** BizarreAlienSenses
** BizarreAlienSexes
* BizarreAlienPsychology
* BlueAndOrangeMorality
* CameFromTheSky
* ChestBurster
* CropCircles
* EldritchStarship
* ETGaveUsWiFi
* ExposedExtraterrestrials
* HigherTechSpecies
* TheMenInBlack
* MirrorChemistry
* MoreTeethThanTheOsmondFamily
* NamedAfterTheirPlanet
* NoBiochemicalBarriers
* SolidGoldPoop
* SpiceOfLife
* StrongerWithAge
* TheyLookLikeUsNow
* TouchedByVorlons
* UnusualEars
* {{Ultraterrestrials}}
* UrsineAliens
[[/index]]
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