Platypuses have no nipples. After the young hatch, the mother oozes milk from the pores all over her body.
The male platypus has a poison barb on the inside of its hind legs. The purpose of this weapon is uncertain.
While often compared to the beaver, the platypus is only about 20 inches in length -- more comparable to the size of the muskrat.
The Platypus bill is actually just an elongated muzzle covered with much the same kind of tough skin found on a dog's nose. This bill contains an electrically-sensitive organ that can detect the electrical signatures of the small aquatic animals it eats.