Measuring 52-54.5 cm, this secretive finfoot species has distinct features. Males display a gray hind crown and neck, a black throat and upper chest with a white border, and a black forecrown with a line along the side of the crown. They have a thick yellow bill with a small horn at the base, mostly white underparts, brown flanks and undertail-coverts with some white bars, dark brown eyes, and bright green legs and feet. Females have a white throat, upper chest, and much of the lores, with less black on the forecrown, no horn, and yellow eyes. Juveniles are browner on the back than females, lack the black forecrown, have less distinct and more mottled black on the neck sides, and a creamy-yellow bill. Their vocalizations include rather high-pitched bubbling sounds during courtship, possibly followed by clucking.