What are the platypus's bills made out of?

Answer 1

The platypus, like any other mammal, is made up of a skeleton, internal organs and an outer covering of skin - in this case, covered with fur. It is not made up of other animals, as some people mistakenly think.

Answer 2

A platypus's bill is not made out of bone or cartilage, but of a leathery skin.