The Gila monster (Heloderma suspectum) lives in California, Arizona, New Mexico, et cetera, as well as in Australia.
The Gila monster typically has a black, scaly skin, with orange stripes. Adult lizards are between 18 and 23 inches (46 to 61 centimeters for our metric friends)long. It also can have salmon-colored stripes, and a pale, almost cream-colored body, depending on breed and such. It's heavily built and moves slowly on four short legs, dragging a thick, short, blunt tail. Fat is stored in the tail, and the lizard can live for months on this reserve.
The Gila monster is one of the only poisonous lizards around (the other known poisonous lizard being the Beaded lizard), but it tries to avoid using its poison. Basically, you don't threaten it, it won't kill you.
Gila monsters eat mostly small rodents, juvenile birds, and bird and reptile eggs. In captivity, however, they usually eat chicken eggs or whatnot.