The Gila monster, Heloderma suspectum is one of two species of venomous lizards found in the world. It is also the only venomous lizard found in the US. Along with the Mexican beaded lizard, Heloderma horridum, comprises the only venomous lizard species known. They are large, colorful, desert-dwelling species of the US southwest and Sonoran desert region of Mexico. Unlike other lizards, the tail of these lizards is not autonomous and does not break off as predator defense. The tail is a fat reserve. A sort of between-meal snack.
The venom apparatus is a series of grooved teeth over which venom flows and is ground into the wound created when these lizards bite.
They can reach lengths of two feet (H. suspectum) to three feet (H. horridum) making the Gila monster the largest lizard in the United States.
It appears that H. horridum has been split into three species recently. Something I was unaware of.
Just a fun fact.
I spent the time in herpetology. Might as well use some of it.