Gila Monster

Category: Wildlife

Shy, secretive animals, Gila monsters are one of the few poisonous lizards in the world.

Gila Monster

Gila Monster

Scientific & Common Names

Kingdom - Animalia

Phylum - Chordata

Class - Reptilia

Order - Squamata

Family - Helodermatidae

Genus - Heloderma

Species - H. suspectum

Common Name - Gila Monster, named for the Gila River basin in Arizona, where they were first found.


Gila monsters are black with pink, orange, or red markings. They have banded tails and spotted heads. Their bright colors send out messages to potential predators that they are poisonous. Gilas are heavy-bodied lizards with large heads, chubby bodies, and fat, stubby tails. They can grow to 24 inches in length and weigh between 3 and 4 pounds.



In late spring or early summer, Gilas mate after performing a courtship ritual. The female then lays between two and 12 eggs underground in the desert sand. The eggs lie underground until the next spring, when they will hatch. The mother does nothing for the eggs. In fact, the heat of the sun is what incubates the eggs. The babies hatch in the spring looking like miniatures of their parents.



Gila monsters are solitary animals and spend most of their time underground in their burrows. They usually emerge only to eat, mate with other Gilas, and to bask in the sun. They eat mammals such as rodents and rabbits, along with bird eggs, small reptiles, and baby birds. Gilas can go months between meals because they store tremendous amounts of energy in the form of fat in their tails. Gila monster venom has been compared to that of the diamondback rattler. When a Gila bites, though, it does not inject poison through fangs. Instead, this lizard latches onto its prey with its powerful jaws and chews on its prey to inject the poison a little at a time.


Ancient Native American tribes from the West depicted the Gila monster on baskets and pottery. Archeologists also have found Gila monster petroglyphs in archeological sites. Some of the native tribes believed that the Gila monster possessed special healing powers in its skin while other tribes believed that the lizards possessed spiritual powers that would cause sickness or death.

Present Status

The Gila monster is not considered an endangered species. However, some places consider them vulnerable, and they are protected under law. People cannot kill or own them with out the correct legal permits. In many places in the Southwest, the habitat of the Gila monster is being destroyed.