Crotalus viridis nuntius is a venomous pit viper subspecies[4] native primarily to the desert plateau of the northeastern portion of the American state of Arizona, but also ranges into northwestern New Mexico.

Named for the Native American Hopi tribe, which inhabits the region, its range overlaps that of the nominate subspecies and some interbreeding is believed to occur.

Their venom is primarily hemotoxic, causing swelling and necrosis, but many populations of C. viridis are known to have a potent neurotoxic effect as well, resulting in muscle paralysis and possibly respiratory failure.

These snakes are ovoviviparous, breeding in the spring and giving birth to small clutches of 4-6 young in the early fall.

Snakes, though not exclusively the Hopi rattlesnake, are used in the ceremony and are released afterwards with the belief that they carry the prayers of the dancers with them.