Reptilian

Reptilians is the name of several different extraterrestrial species in media.
 * Reptoids (aka reptoids, reptiloids, or draconians) from modern mythology that play a major role in both ufology as well as certain conspiracy theories;
 * Lemurians, another race some people consider to actually exist, having lived on the continent of Lemuria;
 * Reptilians from the Godzilla universe;

Similar Species
Other species that could have been described as Reptilians but not directly referred to as such normally are:
 * Argonians from The Elder Scrolls;
 * Agorians from Ratchet & Clank
 * Badoons from Marvel Comics;
 * Cardassians from Star Trek;
 * Cobra-Las, a race that while not inheritantly extraterrestrial, had major dealings with Unicron from the Transformers\G.I. Joe universe;
 * Dracs from Enemy Mine;
 * Draconians from Doctor Who;
 * Drakhs from Babylon 5;
 * Drells from Mass Effect;
 * Foamasis from Doctor Who;
 * Gordanians from DC Comics;
 * Gorns from Star Trek;
 * Harika from Star Control;
 * Hoolefoids from Ratchet & Clank
 * Hork-Bajir from Animorphs;
 * Ice Warrior from Doctor Who;
 * The Jem'Hadar from Star Trek;
 * Kleggs from Judge Dredd;
 * The various Lizardman races from Warhammer Fantasy;
 * Llarans from DC Comics;
 * Naga from Warcraft;
 * Psions from DC Comics;
 * Reapers from Ratchet & Clank
 * Scarrans from Farscape;
 * Skrulls from Marvel Comics;
 * Slademans from Ratchet & Clank
 * Sleestaks from Land of the Lost;
 * Snake Men from the Masters of the Universe... well, universe;
 * The Race from Worldwar;
 * Tosks from Star Trek;
 * Trandoshans from Star Wars;
 * Treens from Dan Dare;
 * Unas from Stargate;
 * Valusians from the Cthulhu Mythos
 * Visitors from the series V;
 * Voths from Star Trek;
 * Xindi-Reptilians from Star Trek;

And a massive number of other extraterrestrial races not mentioned. For example, Star Wars alone has hundreds.