Cottonmouth

The cottonmouth snake (Agkistrodon piscivorus) is also known under the name water moccasin, or a combination of names such as cottonmouth moccasin, highland water moccasin or North American water moccasin. However, the name cottonmouth snake is more precise as water moccasin can be many different types of snakes. It is a relatively large, thick-, and fat looking snake with wide, dark bands along its body. Cottonmouth darkens with age and at some point the bands become obscured. As copperheads they have a greenish tail-tip. The cottonmouth snake is the most aquatic of the Agkistrodon's, although it can be found as far as one mile away from water1.
Some people fear unprovoked attacks from cottonmouth snakes, and other venomous snakes for that snake, but such fears are unfounded. Studies have shown that cottonmouths are unlikely to bite unless being picked up.

Cottonmouths

Agkistrodon piscivorus is a venomous snake, a species of pit viper, found in the southeastern United States. Adults are large and capable of delivering a painful and potentially fatal bite. When antagonized they will stand their ground by coiling their bodies and displaying their fangs. Although their aggression has been exaggerated , on rare occasions territorial males will approach intruders in an aggressive manner. This is the world's only semi-aquatic viper, usually found in or near water, particularly in slow-moving and shallow lakes, streams, and marshes. The snake is a strong swimmer and will even enter the sea, successfully colonizing islands off both the Atlantic and Gulf coasts. The common names for the species include variants on water moccasin, swamp moccasin or black moccasin; viper, cottonmouth and rattler.Many of the common names refer to the threat display, where this species will often stand its ground and gape at an intruder, exposing the white lining of its mouth.
The diet consists mainly of fish and frogs, but is otherwise highly varied and, uniquely, has even been reported to include carrion. The specific name is derived from the Latin words piscis and voro, which mean "fish" and "to eat". Three subspecies are currently recognized, including the nominate subspecies described here.