The adult male of the nominate subspecies, "P. p. pica", is in length, of which more than half is the tail. The wingspan is . The head, neck and breast are glossy black with a metallic green and violet sheen; the belly and scapulars (shoulder feathers) are pure white; the wings are black glossed with green or purple, and the primaries have white inner webs, conspicuous when the wing is open. The graduated tail is black, glossed with green and reddish purple. The legs and bill are black; the iris is dark brown. The plumage of the sexes is similar but females are slightly smaller. The tail feathers of both sexes are quite long, about 12–28 cm long. Males of the nominate subspecies weigh while females weigh . The young resemble the adults, but are at first without much of the gloss on the sooty plumage. The young have the malar region pink, and somewhat clear eyes. The tail is much shorter than the adults.