* Mammary glands: Platypuses, like all mammals, have mammary glands and produce milk to feed their young.
* Fur: Platypuses have fur, another hallmark of mammals.
* Warm-blooded: They are warm-blooded, meaning they can regulate their own body temperature.
* Lay eggs: While this is a unique characteristic that sets platypuses apart from most mammals, it's not a feature exclusive to reptiles. Monotremes (the group platypuses belong to) are the only mammals that lay eggs.
Similarities with reptiles:
* Laying eggs: This is the main reason people sometimes confuse platypuses with reptiles.
* Webbed feet: Platypuses, like many aquatic reptiles, have webbed feet for swimming.
* Beaver-like tail: Platypuses have a flat, beaver-like tail, which is similar in shape to the tail of some reptiles.
However, these similarities are merely convergent evolution, where unrelated species develop similar features due to adapting to similar environments. The platypus is a unique and fascinating animal that evolved its own set of characteristics over millions of years.