Alien Tropes

""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.""

- Sensational She-Hulk #11, Jan. 1990

A character of extraterrestrial origins. For tropes about what makes them alien, see Bizarre Alien Biology.

If you thought it meant "illegal aliens" and signed up, click Race Tropes.

If there are no aliens at all, see Absent Aliens.

Not to be confused with Otherness Tropes.

Tropes
Levels of the ladder of alien strangeness:
 * Human Aliens
 * Human Subspecies
 * Transhuman Aliens
 * Not Quite Human
 * Rubber Forehead Aliens
 * Green-Skinned Space Babe
 * Space Elves
 * Humanoid Aliens
 * Petting Zoo People (sometimes they're aliens)
 * Catfolk
 * Little Green Men
 * The Greys
 * The Reptilians
 * Little Green Man in A Can
 * Insectoid Aliens
 * Intelligent Gerbil
 * Mechanical Lifeforms
 * Alien Animals
 * Blob Monster (amoeba)
 * Killer Space Monkey
 * Space Whale
 * Sand Worm (worms)
 * Big Creepy Crawlies
 * Low Culture, High Tech
 * Plant Aliens
 * Starfish Aliens
 * Eldritch Abomination
 * Silicon Based Life
 * Energy Beings
 * Genius Loci
 * Sufficiently Advanced Alien
 * Insufficiently Advanced Alien

SFX:
 * People in Rubber Suits
 * Muppet
 * Serkis Folk

General tropes:
 * Alien Autopsy
 * Alien Invasion
 * Benevolent Alien Invasion
 * Alternative Number System
 * Anal Probing
 * Brain In A Jar
 * Ditto Aliens
 * Mistaken for Aliens
 * My Brain Is Big
 * Panspermia
 * No Such Thing As Alien Pop Culture
 * People Jars
 * Puppeteer Parasite

Interspecies relations:
 * Aliens Are Bastards
 * Alien Non-Interference Clause
 * Aliens Speaking English
 * Ancient Astronauts
 * Area 51
 * Descriptively Named Species
 * First Contact
 * First Contact Math
 * I Come in Peace
 * Take Me to Your Leader
 * We Come in Peace, Shoot To Kill
 * Innocent Aliens
 * Klingons Love Shakespeare
 * Mistook the Dominant Lifeform
 * Protocol Peril
 * The Right of a Superior Species
 * Roswell That Ends Well
 * Scary Dogmatic Aliens
 * Servant Race
 * Slave Race
 * Superior Species
 * To Serve Man
 * How to Invade An Alien Planet
 * What Measure Is a Humanoid?
 * What Measure Is a Non-Human?
 * The Xenophile

Reproduction:
 * Designer Babies
 * Dying Race
 * Exotic Equipment
 * Face Full of Alien Wingwong
 * Immortal Procreation Clause
 * Interspecies Romance
 * Boldly Coming
 * Gendercide
 * Hot Skitty-On-Wailord Action
 * Mars Needs Women
 * Only You Can Repopulate My Race
 * Uterine Replicator

Genders:
 * Bizarre Sexual Dimorphism
 * Gender Equals Breed
 * One-Gender Race

Other features:
 * Abusive Alien Parents
 * Alien Abduction
 * Alien Among Us
 * Alien Catnip
 * Alien Kudzu
 * Aliens and Monsters
 * Aliens Never Invented the Wheel
 * Aliens Steal Cable
 * Aliens Steal Cattle
 * Amusing Alien
 * Bizarre Alien Biology
 * Bizarre Alien Reproduction
 * Bizarre Alien Senses
 * Came From the Sky
 * Chest Burster
 * Crop Circles
 * ET Gave Us Wi Fi
 * Exposed Extraterrestrials
 * Higher-Tech Species
 * The Men in Black
 * Mirror Chemistry
 * More Teeth Than the Osmond Family
 * Named After Their Planet
 * Solid Gold Poop
 * Spice of Life
 * Stronger With Age
 * They Look Like Us Now
 * Touched By Vorlons
 * Unusual Ears
 * Ultraterrestrials