Agkistrodon contortrix mokasen is a venomous pitviper subspecies found in the eastern United States. Common names: northern copperhead, copperhead, highland moccasin. The Northern copperhead grows to an average length of 61-91 cm (24-36 in), with a maximum of 134.6 cm (52.99 in).
The color pattern consists of an hourglass pattern that runs the length of the body. From above, a series of dark chestnut crossbands look narrow in the center and wider on the sides. Between the crossbands, small dark spots are often present. There are dark rounded spots at the sides of the belly. The head is a copper-red color.
Found in the United States, east Texas, in southern Illinois, extreme northeastern Mississippi, northern Alabama, northern Georgia northeast to Massachusetts, New York Hudson Valley Region, the Appalachian Mountain region and associated plateaus, also southwestern Pennsylvania.
These snakes are generally quiet, almost lethargic, preferring to lie motionless or to make a slow retreat when encountered. When sufficiently agitated, however, they can strike vigorously and may vibrate their tails rapidly.