Merpeople. (Pare, 1678) In Harry Potter's world there have been campaigns to have merpeople rounded up and tagged as “half-breeds”.
Gesner’s masterwork, the History of Animals, nevertheless includes the usual line up of suspect creatures. No doubt some were included, against his better judgement as a naturalist, as a sop to his publisher. Scary monsters, then as now, are just such fun.
The sailor who sent the original sketch of this Sea-Devil to Gesner may in reality have seen a monk seal, once common in the Mediterranean. (Gesner, 1575) The ancient Greek philosopher Aristotle reported accounts of seals raiding orchards.