The common raven (C. corax) is the largest of the perching birds (see passeriform): it reaches a length of up to 66 cm (26 inches) and has a wingspan of more than 1.3 metres (4 feet). (Some magpies and the lyrebird exceed the raven in length, but their bodies are smaller.) In the white-necked raven (C. cryptoleucus) of western North America, the bases of the neck feathers are white. Other species of ravens—some with white or brown markings—occur in Africa, southern Asia, Australia, and North America.

Formerly abundant throughout the Northern Hemisphere, the raven is now restricted to the wilder, undisturbed parts of its range. It is among the hardiest of birds, inhabiting the northern tundra and boreal forests (boreal forest) as well as barren mountains and desert. It is keen-sighted and notably wary. Long before it was immortalized in Edgar Allan Poe's poem "The Raven," the common raven was a near-universal symbol of dark prophecy—of death, pestilence, and disease—though its cleverness and fearless habits also won it a degree of admiration, as evidenced in its noble heraldic roles in the mythology of some peoples.

Like other members of the family Corvidae, the raven is a noisy, aggressive omnivore whose diet includes rodents, insects, grain, and birds' eggs. In winter, especially, it is a scavenger and feeds on carrion, dead fish, and garbage. The raven is an intelligent bird with a large and varied vocabulary, including guttural croaks, gurglings, and a sharp metallic “tok.” The common raven usually is solitary but may feed in small flocks. The raven's spectacular courtship flight involves soaring and all kinds of aerial acrobatics. The birds' crudely made nest of coarse sticks, usually lined with hair or shredded bark, is a bulky structure up to 1.5 metres (5 feet) in diameter that may be built on a cliff or the top of a large tree. The young remain in the nest for about a month. If captured as a nestling, a raven may make an interesting pet capable of learning to mimic a few words. One captive bird on record lived 69 years.