The rough green snake (Opheodrys aestivus) is a nonvenomous North American colubrid. It is sometimes called grass snake or green grass snake, but these names are more commonly applied to the smooth green snake (Opheodrys vernalis). The European colubrid called grass snake (Natrix natrix) is unrelated. The rough green snake is docile, often allowing close approach by humans, and seldom bites.