The Cantil Viper is a medium-sized snake that can grow up to 138 cm, but the average length of the adults ranges between 60 and 70 cm. Their body is robust with a large head, well differentiated from the neck. The species is characterized by its red-orange dorsal color, with a defined series of brown to orange dorsal banding. Two clearly defined lines (white or cream-colored) from the tip of the snout backwards: one of them over the supralabial (scales that border the upper jaw) and the other one on the canthus continuing above and beyond the eye to the neck. These lines give the Cantil Viper a unique appearance which differentiates it from other species of Central American snakes.

The Cantil Viper is a terrestrial species that usually hides under fallen leaves in the forests or near tree trunks and roots on the ground. It uses the oscillating movements of its tail to lure frogs, lizards, and probably rodents, which constitute most of its diet.

The species is found exclusively on dry tropical forests from the South of Mexico down the Pacific coast and up to the Northwestern corner of Costa Rica, where it is found exclusively in the protected territory of the Guanacaste Conservation Area.