The Eastern Diamondback Rattlesnake (Crotalus adamanteus) is a species of venomous pit viper of the family Viperidae. They are native to the forested wetlands of the southeastern United States. The eastern diamondback is the heaviest known venomous snake in the world and the largest species of rattlesnake. They typically reach 1.1 to 1.7 m (3.5 to 5.5 ft) in length and 0.8 to 4.9 kg (1.8 to 10.8 lb) in weight, although the largest specimen measured 2.4 m (7.8 ft) and 15.4 kg (34 lb). An eastern diamondback weighs twice as much as a king cobra of the same length.
The eastern diamondback rattlesnake actively forages or lies in ambush for small animals including rodents, lizards, and birds. Because of their large size, adults have no problem eating prey as large as fully grown cottontail rabbits. Rattlesnakes use neurotoxic venom to shut down the heart and nervous system of their prey. While not especially suited for climbing, they are known to be excellent swimmers.