Brief overview of the Platypus The platypus is a unique, semi-aquatic mammal native to Australia. It is known for its unusual appearance, which includes a bill similar to that of a duck, webbed feet, and a beaver-like tail. Platypuses are also one of the few mammals that lay eggs rather than giving birth to live young. They are primarily nocturnal and feed on a diet of small aquatic creatures, such as insects, crustaceans, and small fish.