A water moccasin, Agkistrodon piscivorus, is a venomous snake that is considered to be highly aggressive and is indigenous to the southern United States. As the name implies, the water moccasin lives near water, and it can swim extremely well. This classification of snake has a variety of common names, such as viper, cottonmouth and swamp moccasin. In an effort to frighten off intruders, a water moccasins will use its coiled body to lift itself to a standing position and will display its large fangs. The strength of this swimmer is so great that it can even swim through oceans to inhabit islands.
Though they are perfectly capable of swimming in an ocean, water moccasins prefer slow-moving waters such as small lakes, marshes, swamps and streams. This type of environment allows easy access to the snake’s main food sources: fish, frogs and small rodents. The water moccasin can even indulge in a meal made of another snake, given the right size and situation. The average size of a water moccasin is about 31 inches (80 cm) long, but the snake can grow to as much as 71 inches (180 cm) long. The water moccasin is very aerodynamic with a head that pushes out slightly past its mouth and a strong, heavy build throughout its body.
The water moccasin typically is black, with the exception of markings on its head, but there are some that are brown, gray, tan or olive. The main color of the snake is further defined by bands of color staggering over the body in dark brown, close-to-black colors. The underside of the snake typically is a light color such as yellow, white or light tan with dark spots. As the snake grows older the bands fade, leaving a near solid, dark color of olive-brown, black or gray-brown.
When the water moccasin is young, it will have well-defined markings and a yellowish-tipped tail. The markings might even be a tan or red brown color. Similar in appearance to the copperhead snake, the juvenile water moccasin has the distinction of broad stripes that run along the side of the head from the eyes. The copperhead snake has a dark line dividing the head from the body. The two snakes can be easily confused without close attention to the details.