The Gila monster (Heloderma suspectum) is one of the two known species of venomous lizards. (The other is the Mexican beaded lizard .) It lives in the deserts of the southwestern USA and northwestern Mexico. The Gila monster is a heavy, slow moving lizard, up to 60 cm (2 feet) long. Its skin has the appearance of beads in the colours black, pink, orange, and yellow, laid down in intricate patterns across the animal's body.

Unlike a snake, the Gila monster injects its venom into the victim not through hollow teeth, but through grooves in the teeth of its lower jaw. It produces only low quantities of a neurotoxin, but by chewing its prey it tries to put as much of the poison into the bloodstream of its victim as possible.

The bite of the animal is normally not fatal to humans, but it can bite quickly and is known to hold on strongly.

The name "Gila monster" refers to the Gila River Basin in Arizona.

Subspecies

There exist two subspecies.

• Heloderma suspectum cinctum , the banded Gila monster
• Heloderma suspectum suspectum , the reticulate Gila monster