It is a medium-sized bird with a long, graduated tail and fairly long bill and legs. The bill and legs are black and the eye is pale yellow. The male is about 31 cm long while the female is 25 cm. The adult male's plumage is entirely black with an iridescent gloss. The gloss is violet on the belly and tail, violet-green on the head, back, and breast, and blue-green on most of the wings. The tail of the male is V-shaped, rising from the centre to the outer feathers. Immature males are duller and less glossy than the adults, with a brown belly and thighs. The female is brown above with a pale supercilium (the stripe over the eye), made more obvious by the dark lores and ear coverts. The thighs, flanks, and undertail coverts are dark brown, while the rest of the underparts are buff, darkest on the upper breast, and paler on the throat and belly.