Agkistrodon piscivorus, commonly known as the cottonmouth or water moccasin, is a venomous snake found primarily in the southeastern United States. It typically inhabits wetlands, swamps, and slow-moving rivers. This species is recognizable by its thick body, triangular head, and distinctive dark coloration, which can vary from brown to black. Cottonmouths are known for their defensive behavior, often opening their mouths wide to display the white interior when threatened. They primarily feed on fish, amphibians, and small mammals, using their venom to subdue prey. Despite their fearsome reputation, they generally avoid human contact.