Rattler

This is a western diamondback rattlesnake. He has been 'resting' on the street for several days. This species is the largest rattlesnake in the West
They are responsible for more bites and deaths to humans than any other rattlesnake species in U.S. The black and white bands ahead of the rattles are an identifying mark.

Thank goodness he is 'resting'! That may be a bullet hole in his neck.