There is a long European tradition of naming animals as if the species were a person. This is perhaps most familiar to us in the names of birds, such as Robin Redbreast, Tom Tit, and Jenny Wren, however this was also common across species, from Tom Cat (coined in the 1300s) to Jack Ass (1620s).
The practice might well have started, in this corner of the world, with the anthropomorphic animals in folktales. Tales of Renard the Fox, Bruin the bear, Baldwin the ass, and Tibert the cat have been popular in Western Europe since the 1100s, each animal with its own personality, and each character's name used colloquially to refer to any arbitrary animal of that sort.
Over time the names change; while male cats were once named Tibert, it later became common to call them Gib-cat, after the popular shortening of Gilbert. Tom, meanwhile, had been popular for male kittens for centuries, but overtook other names for all male cats only in the 1800s. (It was about this time that Tom also started to be used to refer to males of other animals, e.g., tom turkey).
What exactly the meaning of these names are is a bit tricky to define. Renard was a specific entity, whose name was co-opted as an archetype. Robin Redbreast was a playful name for a thrush which was used as a general personification of the animal, but probably in absence of a specific archetype. However, other names were used in later times as less poetic labels; by the time Jack, Jenny, and Jill started to be used for anything from mules to ferrets to kangaroos, it was perhaps more a matter of finding a polite way of refering to the private parts of animals in mixed company.
I had originally hoped to make a comprehensive list of names for animals, but the task turns out to be not just monumental, but nearly undefinable. While surely Margaret Daw
and Jackdaw should be named, and Magpie is a must, Bessie Ducker, Jack Runner, and May Fowl are archaic at best. While Hobbe, the term for a male ferret, is clearly eligible for the list, it would probably require an explanation that in the 1300s Hobbe was a variant of Rob (which is in turn the diminutive of Robert).
Likewise, the appearance of these terms is perhaps more interesting, and meaningful, than any listing of them could be. The flood of new animal names into English in circa 1300-1600 was the result of a new language being constructed from an unholy mix of Old English and Norman French. It is surprisingly difficult to find what the Old English name for a Robin Redbreast was, but it was probably not named after a person. We do know the general term, because we kept the Old English term 'thrush' (þræsce), but the thrush with the bright red chest (red thrush?) was renamed Robin Redbreast , while the song thrush was simply named Mavis -- good French-derived names that mirrored the more general linguistic shift of the times.
Following this came centuries of English speakers who were happy to play around with animal names, but did so in a less systematic way. The result is a confusing mix that defies categorization. Jenny Wren (Robin's consort in folklore, despite the difficulty of interspecies dating), ended up giving her name to more and more animals, including herons, jays, and donkeys. Some of the best known animal names are quite recent, e.g., Nanny goat (1788) and Billy goat (1826), and some are still new enough that they might not stick, e.g. Peter Rabbit (1893) and Felix the Cat (1919), Fido (1866), and Rover (1905).
And then, of course, there are the weird terms that don't quite fit anywhere. The French name Parrot appeared in the 1520s, possibly arising as a variant of Pierre. It replaced the much more pleasing (but also French) term popinjay, which rather seems to go against the prevailing trend. 'Jay' itself is interesting because it is a proper French word refering to the European jay (c. 1200s) borrowed directly into English as a surname (also 1200s), which eventually came to be used in the 1400s to refer again to the bird. The bird's name was eventually extended to jaybird in the 1660s, presumably to avoid confusion. And, of course, there is the confusing matter of Ralph.