This small rattlesnake only reaches lengths of 1-2 feet long, a dwarf amongst its relatives. It is distinguished from similar species by a smaller adult size, more bands around the tail, and fewer, often smaller scales around the body.

This species is only found on Cabeza de Caballo Island off the eastern coast of Baja California. Their diet entirely consists of lizards. The exceptionally smaller size is likely due to the small size of the island, the size of their prey, and a lack of mammalian predators with an increase of avian predators on the island.

Fun fact: This species was only recently described in 2018 and was named after the late Gary A. Polis who died after his research vessel capsized returning from Cabeza de Caballo Island. He was a renowned arachnologist and desert food-web ecologist.