Heloderma

Heloderma is a genus of toxicoferan lizards that contains five species, all of which are venomous. It is the only extant genus of the family Helodermatidae.

==Description== The genus Heloderma contains the Gila monster (H. suspectum) and four species of beaded lizards. Their eyes are immobile and fixed in their heads. The Gila monster is a large, stocky, mostly slow-moving reptile that prefers arid deserts. Beaded lizards are seen to be more agile and seem to prefer more humid surroundings. The tails of all species of Heloderma are used as fat-storage organs. The scales of the head, back, and tail are bead-like, containing osteoderms for better protection. The scales of the belly are free from osteoderms. Most species are dark in color, with yellowish or pinkish markings.