Water moccasin

Water moccasin, also called cottonmouth or moccasin snake, poisonous snake in the viper family. This species (Agkistrodon piscivorus) lives in the southeastern United States in swampy or marshy areas of rivers, streams, and lakes. It may grow between 3 1/2 ft (107 cm) and 5 ft (1.5 m) long. It is considered a pit viper because of a hollow pit located between the eye and nostril on the side of its head. Its often fatal bite may be preceded by a warning, which involves the exposure of the white, cottonlike inside of its mouth.