Northern water snake The belly also varies in color. It can be white, yellow, or gray. Usually it also has reddish or black crescents. The northern water snake is nonvenomous and harmless to humans, but superficially resembles the venomous cottonmouth and is often killed unnecessarily as a result of this mistaken identity. The two can be easily distinguished by morphological traits: the water snake has a longer, more slender body and a flattened head the same width as the neck, round pupils, and no heat-sensing pits. The cottonmouth has a fatter body, a wedge-shaped head with prominent venom glands that are wider than
Brown water snake Brown water snake The brown water snake ("Nerodia taxispilota") is a large species of nonvenomous natricine snake endemic to the southeastern United States. "Lycodonomorphus rufulus" is sometimes also called the brown water snake, but "L. rufulus" is found in South Africa. Brown water snake, water-pilot, aspic, false moccasin, great water snake, pied water snake, southern water snake, water rattle. "Nerodia taxispilota" is found in lower coastal regions from southeastern Virginia, through North Carolina, South Carolina, and Georgia, to northern and western Florida (Gulf Coast), then west through Missouri, Alabama and Mississippi, to Louisiana, normally from sea level to 500 ft.