The platypus is a strange duck-billed mammal with webbed feet and a furry body like a beaver. It has characteristics of birds, mammals, and reptiles. Females lay eggs but also nurse their young with milk. Males produce a potent venom.

When Europeans discovered the platypus in Australia in 1798, they wrote letters to folks at home to describe this bizarre new animal. People thought the platypus was a joke or a hoax—because it didn’t fit into the classification of animals at that time.

But it was a real animal.