Agkistrodon contortrix is a species of venomous snake, a pit viper, endemic to Eastern North America; it is a member of the subfamily Crotalinae in the family Viperidae. The common name for this species is the eastern copperhead. The generic name is derived from the Greek words ancistro (hooked) and odon (tooth), or fishhook. The trivial name, or specific epithet, comes from the Latin contortus ; which is usually interpreted to reference the distorted pattern of darker bands across the snakes back, which are broad at the lateral base but "pinched" into narrow hourglass shapes in the middle at the vertebral area. Five subspecies have been recognized in the past, but recent genetic analysis shows that A. contortrix and two of the subspecies are monotypic, while Agkistrodon laticinctus and the fifth subspecies are a single distinct species.
