The Crotaphytidae, or collared lizards, are a family of desert-dwelling reptiles native to the Southwestern United States and northern Mexico. Alternatively they are recognized as a subfamily, Crotaphytinae, within the clade Pleurodonta. They are very fast-moving animals, with long limbs and tails; some species are capable of achieving bipedal running at top speed. This species is carnivorous, feeding mainly on insects and smaller lizards. The two genera contain 12 species.

The common collared lizard, also commonly called eastern collared lizard, Oklahoma collared lizard, yellow-headed collared lizard, and collared lizard, is a North American species of lizard in the family Crotaphytidae. The common name "collared lizard" comes from the lizard's distinct coloration, which includes bands of black around the neck and shoulders that look like a collar. Males can be very colorful, with blue green bodies, yellow stripes on the tail and back, and yellow orange throats. There are five recognized subspecies.