plat·y·pus 
(plătĭ-pəs)
(plătĭ-pəs)n. pl. plat·y·pus·es
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.
[New Latin Platypūs, former genus name, from Greek platupous, flat-footed : platu-, platy- + pous, foot; see ped- in the Appendix of Indo-European roots.]