The Knob billed Duck (Sarkidiornis melanotos), a large and distinctive waterfowl recognized by the bold black knob on the male's bill. This comb like structure becomes more prominent during breeding season and likely helps Knob billed Duck Talking about an odd duck, well than I got one for you: the knob billed duck! How weird and cool does the male look? And their colours and spots on both of male Details : Knob billed Duck BirdGuides This bird wears its crown not of feathers, but of horn. The Knob billed Duck (Sarkidiornis melanotos), also known as the Comb Duck, is one of the most unmistakable waterfowl in the world.