The water moccasin, also known as the cottonmouth, is a venomous snake found primarily in the southeastern United States. It typically inhabits wetlands, swamps, and slow-moving rivers. This snake is recognizable by its thick body, triangular head, and dark coloration, which can vary from brown to black. Water moccasins are known for their defensive behavior, often displaying their white mouths when threatened. They are semi-aquatic and are excellent swimmers, using their strong bodies to navigate through water. Their diet mainly consists of fish, amphibians, and small mammals, making them important predators in their ecosystems.