Whale headed stork, a species of the genus Whale headed stork in the family Whale headed stork of the order Storksiformes. Whale headed cranes, also known as "whale faced storks," "boot billed storks," or "father of shoes," are the largest surviving bird species in terms of head. The adult feathers of the Whale headed Stork are mainly gray, of the same color as males and females, with a green luster on the back. The feathers of the young birds are mainly brown, with no green luster on the back. The tail is short and there is a short crest behind the head. The mouth color is mostly yellow green, rainbow white to light yellow, and the feet are black. The most prominent feature of its appearance is its large head and thick, wooden boot like mouth, named after its powerful beak.