Beast myths have many origins. The ones most interesting to me are the embedded cultural myths but then there are the so-called Jenny Haniver types. Purportedly found carcasses of strange creatures that are, in fact, hoaxes of taxidermy. Probably the most famous of these is Jake the Alligator Boy along with preserved mermaids, etc. Ebay is wonderful for finding creatures you didn't know exist. Witness the creature above, "discovered" washed up on a beach.