The backside of the Harpy Eagle is covered with slate black feathers, and the underside is covered with white. There is a black band across the chest up to the neck. The head is pale gray, and is crowned with a double crest. This coloration gives it the menacing look to match its reputation.
The Harpy Eagle is one of the largest of the fifty species of eagles. It can grow to be as large as 36 to 40 inches in length (this mainly is seen in the females of the species). It can reach a weight up to 20 pounds. The harpy in flight can reach speeds above 50 mph. The Harpy is relatively half the length of an average-sized human, and it is this size that makes them formidable hunters.
The Harpy Eagle, due to living in forests, has short wings. These wings are used for speed and maneuverability. They weave in and out of the trees, launching surprise attacks on their prey. They use the trees for cover. They also possess enormous grasping claws, and these are used for perching as well as for snaring prey.