The Northern Pacific Rattlesnake is a venomous species of Rattlesnake found in the Western United States.
Juveniles usually have more or less distinct patterns, but these fade as the animals mature. The color of the iris often matches the ground color, which may be bronze, gold, or different shades of tan, pink, or gray.
The color pattern of the typical form the Northern Pacific Rattlesnake has is a dark-brown, dark-gray, olive-brown, or sometimes black or pale yellowish ground color overlaid dorsally with a series of large, dark blotches with uneven white edges. These blotches are also wider than the spaces that separate them. Additionally, a lateral series of blotches, usually darker than the dorsal blotches, is clearly visible on all but the darkest specimens. The first rings of the tail are about the same color as the last body blotches, but these rings become progressively darker; the last two rings, at the base of the tail, are usually black. The belly is pale yellow, usually with brown spots. There is a dark brown postocular stripe with a white border that extends from the eye to around the angle of the jaw.
The Northern Pacific Rattlesnakes diet includes birds, and small mammals, from mice up to and including rabbits. Insects, too.