+/- 1 m, 3-4 kg, Males slightly larger than females, but sexes alike in plumage.
Spiky straw coloured crest, tipped with black. Dark grey to slate body, lighter grey neck. Distinctive large white wing patches, edged in black, rust brown and yellow (straw colour). Head mainly black with white cheeks and red wattles. Iris white to pale grey. Bill, legs and feet black. Cheeks bare and white.
Voice Characteristic 2 syllabled trumpeting ma-Hem