Fer-de-lance, a venomous snake of Central and South America and the West Indies. The fer-de-lance is related to the pit viper and rattlesnake, but has no rattles. It is named for its lance-shaped head. The fer-de-lance grows to a length of six feet (1.8m). It is gray, olive, or brown above and white or cream below. The back is marked with dark blotches.

The fer-de-lance hides in a hole in the ground or under plants during the day and hunts at night. It preys on small mammals, birds, frogs, and lizards. The females give birth to living young. As many as 70 young, about one foot (30 cm) long, are born at a time. The young take care of themselves from birth. The fer-de-lance is preyed upon by armadillos and hog-nosed skunks.

There are at least two species of fer-de-lance—Bothrops atrox and B. andianus. They belong to the subfamily Crotalinae of the viper family, Viperidae.