List of prominent alien species
| Gray aliens
||Grays tend to vary from account to account, but depictions usually contain most of the following characteristics: gray skin (duh); a bulbous head; a lack of hair; and large, black, almond-shaped eyes, with the nose, mouth, ears and sex organs rudimentary or absent. Grays are often, but not always, naked; their stature and overall demeanor tends to vary, with some depicted as tall and graceful and others as squat and dwarfish. Most accounts describe them as small, about the size of a nine-year-old human child.|
|"Little green men"||Exactly what it says on the tin. The "default alien", usually from Mars, before everyone started watching The X-Files and seeing "Grays" under every bed (though possibly, little green men simply blew themselves and their civilization up). One wonders how they had time to visit Earth what with their hydraulic and monumental art projects on Mars. Some newer versions have them as essentially green versions of the Grays (an alien version of Andy Serkis?).|
||Pleiadians are supposed to be better-looking versions of us. They nearly always lack pigmentation in their skin and hair, giving them an albino appearance. They are said to have either a Nordic/"Aryan" appearance, or an Asian appearance similar to Grays. As a rule, Pleiadians don't carry around much excess fat, although females are known to have curvy figures. They don't usually have curly hair or beards.|
|Reptilians||Tall, scaly humanoids. With so many idiotic, crazy, implausible conspiracy theories out there, this still manages to be particularly stupid, with claims that these reptiles are actually shape-shifters and that any number of prominent people are "really" reptilians in disguise as "proven" by the "occasional failure" of their camouflage (what sane people living in the real world call camera glitches, such as the red eye phenomenon and similar optical quirks).|
- Bryan, C.D.B (1995). Close Encounters of the Fourth Kind. Alfred A. Knopf, Inc. ISBN 9780679429753.
- Blackmore, Susan (May 1998). "Abduction by Aliens or Sleep Paralysis?". Skeptical Inquirer (Amherst, NY, 14226, US: Committee for Skeptical Inquiry) 22 (3). ISSN 0194-6730. OCLC 4081591. http://www.csicop.org/si/show/abduction_by_aliens_or_sleep_paralysis. Retrieved 2015-06-02. "The '[G]ray' is about four feet high, with a slender body and neck, a large head, and huge, black, slanted, almond-shaped eyes. Grays usually have no hair and often only three fingers on each hand."
- Carlson, Peter (February 19, 2004). "Ike and the Alien Ambassadors". Washington Post. http://www.washingtonpost.com/ac2/wp-dyn?pagename=article&contentId=A53203-2004Feb18¬Found=true. Retrieved 2007-03-30.
- Delasara, Jan (2000). "The X-Files and the Zeitgeist of the '90s". PopLit, PopCult, and the X-Files. McFarland. p. 187. ISBN 0-7864-0789-1. http://books.google.com/books?id=7aKTJljercgC&pg=PA187&dq=nordics+space+brothers.