Copperhead (trigonocephalus contortrix, Linn.; genus agkisirodon, Bd. and Gd.), a North American venomous serpent, the most dangerous after the rattlesnake. The head is thick and triangular; it has a pit between the eye and the nostril; the upper jaw furnished with poisonous fangs; the eyes large, and the orbital plates projecting; the iris is bright golden with a reddish tinge. The neck is contracted, and its scales are smooth; the body long, thick to near the tail, and covered above with rhomboidal carinated scales, except the lower rows, which are smoother; the last abdominal plate is very large; there are no rattles, the tail being short and conical, ending in a horny tip. The general color above is a light nut-brown, with transverse bars of dark brown, narrowest in the middle, broad and bifurcated on the sides; the under parts are flesh-colored, freckled with minute dark brown spots; near the flanks are rounded dark blotches, corresponding to the bifurcations of the dorsal bars. In a specimen 26 inches long, the head measured a little more than an inch in length by 11 lines in width; length of body 21 inches, and of tail 3 1/2 inches; greatest circumference 3 1/2 inches; the abdominal plates were 150, and the subcaudal 42, with 4 pairs of bifid scales near the apex.
It prefers dark and moist places, and feeds upon lizards, frogs, mice, and small birds. It is more dreaded than the rattlesnake, as it gives no warning of its proximity; it never attacks man except in its own defence; as with other venomous snakes, a very slight blow is sufficient to kill it. From its thick body and short tail, it is slow and clumsy in its motions, and it cannot ascend trees. It is also called "chunkhead" and "deaf adder." According to Dr. Holbrook, it is found from western New England to Florida, and from the Atlantic to the borders of the Alleghanies.