The North American Porcupine is a large rodent in the New World porcupine family. The Beaver is the only other rodent larger than the North American Porcupine found in North America.

This animal is usually found in coniferous and mixed forested areas in Canada, Alaska and much of the northern and western United States. They are also found in thicketed areas in shrublands, tundra and deserts as far south as northern Mexico. It makes its den in a hole in a tree or in a rocky area.

Porcupines are usually dark brown or black in colour, with white highlights. They have a chunky body, a small face, short legs and a short thick tail. Their upper parts are covered with thousands of sharp, barbed hollow spines or quills, which are used for defense. Porcupines do not throw their quills, but the quills detach easily and the barbs make them difficult to remove once lodged in an attacker. The quills are normally flattened against to the body unless the animal is disturbed. The porcupine also swings its quilled tail towards a perceived threat.

Porcupines are mainly active at night; on summer days, they often rest in trees. During the summer, they eat twigs, roots, stems, berries and other vegetation. In the winter, they mainly eat conifer needles and tree bark. They do not hibernate but sleep a lot and stay close to their dens in winter. The strength of the porcupine's defense has given it the ability to live a solitary life, unlike many herbivores.

Porcupines breed in the fall and the young porcupine (usually one) is born in the spring, with soft quills that harden within a few hours after birth.

They are considered by some to be as a pest because of the damage that they often inflict on trees and wooden and leather objects. Plywood is especially vulnerable because of the salts added during manufacture. They move slowly and are often hit by vehicles while crossing roads. Natural predators include fishers, wolverines, coyotes, and mountain lions.