The Oaxacan pygmy rattlesnake is a small species of rattlesnake found in the mountains of Oaxaca. This species can be distinguished from the two other species of Mexican pygmies by its 5-8 tail bands and undivided parietal scales (behind the eyes). It inhabits mixed oak-pine forests and semi-arid scrublands. As a generalist predator, it eats a variety of prey including rodents, lizards and sometimes insects.

This species was only elevated to full species status in 2018-- it used to be a subspecies of Crotalus ravus. There was sufficient genetic evidence to warrant this snake to be its own unique species!

This species is threatened by habitat loss, particularly the use of fire to clear woodlands for agriculture. Human persecution also plays a role in the decline of this species.