this link leads to info regarding how the animal was initially considered a hoax being played on European scientists and naturalists by sailors
" . . . The surgeon Robert Knox later explained that because the specimens arrived in England via the Indian Ocean, naturalists suspected that Chinese sailors, who were well known for their skill at stitching together hybrid creatures, might have been playing some kind of joke upon them. (See the Feejee Mermaid hoax.) "Aware of the monstrous impostures which the artful Chinese had so frequently practised [ sic ] on European adventurers," Knox noted, "the scientific felt inclined to class this rare production of nature with eastern mermaids and other works of art." . . .
The Duckbilled Platypus (1799)