The platypus is among nature's most unlikely animals. In fact, the first scientists to examine a specimen believed they were the victims of a hoax. The animal is best described as a hodgepodge of more familiar species: the duck (bill and webbed feet), beaver (tail), and otter (body and fur). Males are also venomous. They have sharp stingers on the heels of their rear feet and can use them to deliver a strong toxic blow to any foe.

Platypuses hunt underwater, where they swim gracefully by paddling with their front webbed feet and steering with their hind feet and beaverlike tail. Folds of skin cover their eyes and ears to prevent water from entering, and the nostrils close with a watertight