Crotalus lepidus is a venomous pit viper species found in the southwestern United States and northern central Mexico.

It has a large, rounded head, and fairly heavy body for its size, with eyes with vertical pupils.

Specimens of the mottled rock rattlesnake (C. l. lepidus) from the Davis Mountains region often exhibit a more pink coloration, with dark-grey speckling rather than distinct banding.

The type locality given is "Presidio del Norte and Eagle Pass" (Texas, USA).

They tend to rely heavily on their camouflage, and will often not strike or even rattle their tails unless physically harassed.

Two subspecies, C. l. lepidus and C. l. klauberi, are frequently available in the exotic animal trade, and are well represented in zoos around the world.

[citation needed] While not type-specific, the polyvalent antivenin CroFab is generally used to treat serious envenomations.

A recent review [6] showed that the Tamaulipan rock rattlesnake appears to be a separate species, Crotalus morulus