Agkistrodon piscivorus, commonly known as the cottonmouth or water moccasin, is a venomous snake found in the southeastern United States. It thrives in wetland habitats such as swamps, marshes, and slow-moving streams. This semi-aquatic species is notable for its aggressive defense behavior and distinctive white mouth display when threatened. Cottonmouths are also recognized for their heavy bodies, keeled scales, and a pattern that darkens with age, often resulting in a deep, uniform black or brown color in adults.

Agkistrodon piscivorus, commonly known as the cottonmouth or water moccasin, is native to the southeastern United States. Its geographical distribution includes the states from Virginia to Florida, west to Texas, Oklahoma, and parts of Illinois, Indiana, and Missouri.

The cottonmouth is typically found in wetland environments such as swamps, marshes, and the edges of lakes, ponds, and slow-moving streams. It prefers areas with abundant water and dense vegetation, which provide cover and hunting opportunities.

Agkistrodon piscivorus is a semi-aquatic pit viper, meaning it is adapted to both aquatic and terrestrial habitats. It is an opportunistic predator, feeding on fish, amphibians, small mammals, birds, and other reptiles. Its ability to thrive in a variety of wetland environments makes it an important predator in maintaining the balance of ecosystems in its native range.