platypus (n.) Look up platypus at Dictionary.com
Australian duck-mole, 1799, from Modern Latin, from Greek platypous, literally "flat-footed," from platys "broad, flat" (see plaice (n.)) + pous "foot" (see foot).
Orig. the generic name, but, having already been given to a genus of beetles, it was in 1800 changed for Ornithorhyncus. [OED]