Gila Monster
Heloderma suspectum
Description: 18-24" (45.7-61.0 cm). Large and heavy-bodied. Small beadlike scales on back. Broken blotches, bars, spots of black and yellow, orange, or pink, with bands extending onto blunt tail. Face black.
Warning: The venom secreted when a Gila Monster bites causes great pain and localized swelling, but is rarely fatal to humans. It is the persistent grip of a Gila Monster's jaw that makes it dangerous to attempt to handle these animals.
Subspecies: Reticulate Gila Monster (H. s. suspectum), adults mottled and blotched; c. and s. Arizona and adjoining New Mexico.
Banded Gila Monster (H. s. cinctum), adults have broad double crossband; sw. Utah through s. Nevada and adjoining California and w. Arizona.
Breeding: Mates throughout summer months. 3-5 eggs are laid, fall to winter.
Habitat: Arid and semiarid regions of gravelly and sandy soils, especially areas with shrubs and some moisture. Found under rocks, in burrows of other animals, sometimes in holes it digs itself.
Range: Extreme sw. Utah, s. Nevada and adjacent California, south through s. Arizona and sw. New Mexico to Mexico.
Discussion: Primarily nocturnal, although also active on warm winter or spring days. Gila Monsters and the related Mexican Beaded Lizards are the only venomous lizards. Their bite serves to overpower animal predators and prey. Produced in glands lying along the lower jaw, the poison is not injected like that of a snake but flows into the open wound as the lizard chews on its victim. Most prey is small enough to be taken easily without venom: small birds, eggs, small rodents, and other lizards.
Source
