This bird, large for a wood rail, has both a grey head and, as the name implies, neck. In the nominate, the back of the head has a brown patch. The upperparts are olive-green to dark brown. The chest and flanks are a rufous colour, with the belly, rump, and tail being black. The legs are coral-red, the bill is a bright greenish-yellow, and the eyes are red. The sexes are similar. The juveniles can be differentiated by their duller look, and the chicks have a black, downy appearance, brown head, and black beak.
This bird feeds at night. While in mangroves, it commonly feeds on crabs. Other-wise, it will generally feed on snails, spiders, crustaceans, frogs, seeds, berries, palm fruits, and the occasional water snake. Maize, rice, and bananas are also viable food items.