The significance of using animal names in this context is that these two pieces are the "Beast" pair. I'd feel silly using the Teutonic Knight or Very Heavy Chess names and calling them beasts.
Note that, as H.G. suggests, the beasts aren't necessarily of the same family: already it's Kirin -> Tiger -> Unicorn and Phoenix -> Elephant -> Buffalo. If they went on to be Penguin and Tasmanian Devil or even Babe the Blue Ox and the Loch Ness Monster, it wouldn't be out of place.
PS: Not that it matters so much, but I still favor "Abbess" over "Popess." :)
The significance of using animal names in this context is that these two pieces are the "Beast" pair. I'd feel silly using the Teutonic Knight or Very Heavy Chess names and calling them beasts.
Note that, as H.G. suggests, the beasts aren't necessarily of the same family: already it's Kirin -> Tiger -> Unicorn and Phoenix -> Elephant -> Buffalo. If they went on to be Penguin and Tasmanian Devil or even Babe the Blue Ox and the Loch Ness Monster, it wouldn't be out of place.
PS: Not that it matters so much, but I still favor "Abbess" over "Popess." :)