Adult cottonmouth snakes are usually longer than three feet, with rare specimens reaching over six feet.
Poisonous serpents, such as the cottonmouth and copperhead, will have slit pupils.
Among venomous snakes the harlequin, or coral snake (Elaps fulvius) is common along the coast; the copperhead (Agkistrodon contortrix) along the wooded banks of creeks and rivers; the cottonmouth (Agkistrodon piscivorus), in all parts of the state except the more arid districts; the "sidewiper," or massasauga (Sistrurus catenatus consors, sometimes called Crotalophorus tergeminus) and the ground rattlesnake (Sistrurus miliarius), in all sections.