Platypi vs. Platypuses — What's the Difference?

(hypercorrect) platypus

A semiaquatic egg-laying mammal (Ornithorhynchus anatinus) of eastern Australia and Tasmania, having a broad flat tail, webbed feet, a snout resembling a duck's bill, and in the male, venomous spurs on the hind legs. Also called duckbill, duck-billed platypus.

Plural of platypus