Within these classifications he develops separate types , and under that, variants . Humanoids include humanlike beings or Nordics, short grays, short non-grays, giants, and a nonclassic catchall group containing a solid black form, mummylike creatures, as well as a handless being. These creatures are placed with humanoids because they exhibit the same basic body structure as a human. Animalian classes may be hairy, scaly, move on four legs, or have wings. Animalians include hairy mammalian, reptilian, amphibian, insectoid, and avian.
Robotic creatures have a characteristic mechanical nature to their movements.
Robotic Aliens include metallic types looking like tin cans or slabs of metal. Fleshy Robotic types have android characteristics of either humans or animals, such as humanlike arms or legs or scaly skin of a reptile. Exotic entities represent a catchall group of Aliens which would not be considered humanoid, Animalian, or Robotic. Exotic Aliens include apparitional or physical types. Apparitional types include ghostlike images or nonhumanoid creatures that are only partially formed or appear to exist in another dimension.