Gila monsters are the largest lizards native to the United States. They get their name from Arizona's Gila River basin, where they were first discovered. Gila (pronounced hee-la) monsters are also one of only two venomous lizards in the world.
Their heads and necks are broad and their eyes are black with round pupils. Their bodies are covered with beaded scales and bright black, pink, yellow and orange patterns. Their wide feet end with long, sharp claws.
Gilas spend around 95 percent of their lives in their homes, which are underground burrows located in rocky foothills, according to National Geographic.
When a Gila monster is active depends on the weather. If it's a really hot day, the lizard may choose to only come out at night. If it's a cooler day, the other hand, the lizard may make an appearance while the sun is up.
Gila monsters take three to five years to mature and live 20 to 30 years.
A Gila monster has long, sharp claws. (Image credit: Timothy Craig Lubcke/Shutterstock )
If they can't get out of their burrow to forage, no problem. Gilas store fat in their tails and can go for months without food. They especially use this trait during the winter and will stay inside all season long.
When it does eat, it goes big. A Gila monster can gulp down a third of its body weight in one meal, according to the San Diego Zoo.
The bite is described as extremely painful, but the poison isn't deadly to humans in most cases. The pain is generally confined to the bite area, according to Arizona's Poison Center. It also may cause localized swelling, nausea, vomiting, high blood pressure, weakness, faintness, excessive sweating, chills and fever.
Currently, there is no antivenom for Gila monster bites. The first step to treatment is making the lizard let go. A strong stick to pry apart the jaws is recommended. First aid may include irrigating the wound with water and immobilizing the affected limb at heart level. The wound should be checked for broken teeth. Anyone bitten by a Gila monster should seek immediate medical treatment.
Kingdom: Animalia Subkingdom: Bilateria Infrakingdom: Deuterostomia Phylum: Chordata Subphylum: Vertebrata Infraphylum: Gnathostomata Superclass: Tetrapoda Class: Reptilia Order: Squamata Suborder: Autarchoglossa Family: Helodermatidae Genus: Heloderma Species: Heloderma suspectum Subspecies: Heloderma suspectum cinctum (banded Gila monster), Heloderma suspectum suspectum (reticulate Gila monster)
The United States and Mexico prohibit the collection of Gila monsters throughout their range, according to the IUCN. Sizable areas of habitat are protected from development in national parks and monuments and in federal wilderness areas.
Gila monsters can only run about 1 mph (1.6 km/h).
Though not the most active animal, Gilas are more than willing to climb a cactus to get to a nest full of eggs.
The bead-like scales that cover Gilas are called osteoderms. The bright colors of these scales are thought to warn predators to stay away, much like the bright colors of poisonous frogs.
Gilas use their big tails for balance while they walk.
There is a drug for the management of Type 2 diabetes based on a protein from Gila monster saliva. The drug has the nickname "lizard spit," according to the San Diego Zoo.
Additional resources
Potter Park Zoo: Gila MonsterU.S. Library of Medicine: The Development of Byetta (Exenatide) from the Venom of the Gila Monster as an Anti-diabetic AgentThe Atlantic: Arizona's Adorable Monster