18. Black moccasin, cottonmouth, swamp moccasin (Agkistrodon piscivorus)
This snake inhabits southeastern part of the Northern American continent. It prefers wetlands including marshes, bays, lakes and areas around creeks, where they get in touch with humans. Cottonmouth is a thick-bodied snake with the average length of around 90 centimeters. They are usually even and dark in color, though some have crossband pattern.
