A large, mostly black goose with variable amounts of white on the throat, neck and belly. In flight, its huge size and the large white area in the forewing distinguish this species from Comb Duck.
Male is much largen than female, and its facial skin extends behind the eye. Juvenile and immature are like adult but browner.
frequents water bordered by grassland and agricultural areas. Feeds ashore, often at night, on grasses and other vegetable matter.
A feeble, wheezy whistle given in flight.