The Platypus or the Duck billed Platypus is basically a semi-aquatic animals which is classified as a mammal. It is one of the five extinct specie of monotremes. It is the only animal classified as a mammal even though it lays an egg instead of giving birth to a baby.
When Platypus was discovered, the scientists were divided over whether it is a mammal or it laid eggs. When they actually found it laid eggs, it was still classified as a mammal. This is because its features are like mammals. It has hair around its whole body. It has mammary glands which help it to make milk for its children. It is categorized as warm blooded because it has a good temperature control.