Literally 'duck-mouth-beast': 鸭 duck + 嘴 mouth + 兽 beast. The Chinese name describes exactly what makes the platypus weird, a beast with a duck's bill, and is much more transparent than the Greek-derived English 'platypus' ('flat foot').
culture
When Europeans first sent a platypus skin to the British Museum in 1799, scientists thought it was a hoax stitched together from a duck and a beaver. The Chinese name captures that same first-impression bewilderment.