The Crested Serpent Eagle is a medium-sized bird of prey that is found in forested habitats across tropical Asia. They fly over the forest canopy on broad wings and tail have wide white and black bars. They call often with a loud, piercing and familiar three or two-note call. They often feed on snakes, giving them their name.
This medium-large, dark brown eagle is stocky, with rounded wings and a short tail. Its short black and white fan-shaped nuchal crest gives it a thick-necked appearance. The bare facial skin and feet are yellow. The underside is spotted with white and yellowish-brown. When perched the wing tips do not reach until the tail tip. In soaring flight, the broad and paddle-shaped wings are held in a shallow V. The tail and underside of the flight feathers are black with broad white bars. Young birds show a lot of white on the head. The tarsus is un-feathered and covered by hexagonal scales. The upper mandible does not have an overhanging festoon to the tip.