It’s big, it’s weird, it’s almost certainly a seal and it has a really unfortunate name! This is the Bayfart, and Thevet picked up a skin from near Denmark. He describes it as having bristles around its nose, a single horn on its head (Seel? Is that you?), claws on its forelegs, and a twin-tailed rear. Very pinnipedian.
But Thevet also says that “bayfart” is its name in the language of Finnmark. So I ask this to any Scandinavian readers – is there any word that could realistically have been garbled into “bayfart”?