Oklahoma designated the collared lizard (Crotaphytus collaris) as the official state reptile symbol in 1969. Also called mountain boomer because it was mistakenly thought to emit a sound that echoed through mountain valleys.

A relatively long-lived lizard known to run upright on its hind legs, which givies the appearance of a miniature T. rex. Collared lizards also wave their tail, much like a cat, before grabbing their prey.

Prominent black bands behind the head give the lizard its name. The male's body is green and the head may be bright yellow. The male also has a brightly colored throat (blue, green or even orange), and may have blue patches on the belly, with sprinklings of white, yellow or red. Females are generally fawn or gray, taking on red or salmon-colored speckling during breeding season.

Source:

Collared Lizards: Melissa Kaplan's Herp Care Collection

Links:

State Reptiles & Amphibians - 50 States List