In ufology, Alien Greys, also known as Greys, Roswell aliens, Zetas, and Reticulians, are alleged extraterrestrial life forms that appear in modern UFO conspiracy theories and other UFO-related paranormal phenomena. Said to be one of several species of aliens, Greys make up approximately 75 percent of all aliens reported in the United States, 2 percent of all aliens reported in Continental Europe, and 12 percent of all aliens reported in Great Britain. In American popular culture they have replaced little green men as the most typical extraterrestrial life form. Sometimes, in sci-fi and cartoons, Greys have been shown as stereotypical aliens.Grey aliens are a extremely violent type of alien, in some cases, often reacting to fear or hostility with equal display of ill intention.