As a zoo-lover myself, I quite like wearing evening renditions of Belgian slippers out at night, black tie or no. Belgians, particularly of the velvet variety, carry much of the elegance of evening wear without being quite so particular as the evening pump, which has a higher heel and shows more of the foot (see examples here and here). What's more, they're insanely comfortable.
Once you get over the daintiness of the style, you'll find yourself lusting after every pair of Belgians you come across. The reason is that they are virtually unique as shoes that work well in colors other than black and brown, and materials other than calf, shell, and suede.
The possibilities are, however, limited by two factors other than one's own imagination and aversion to frivolous decadence. First, there aren't too many places to find Belgians. Mine are the soft-soled variety from Belgian shoes in New York. I also have a pair from ASW. Rubinacci also makes a black velvet version of their Belgians. Each offers quite a wide array of models, but still it would be nice to have more options. One thing these have in common is that they'll set you back around $400, which is the second limiting factor. That's quite a lot to lay down for a shoe that isn't terribly versatile nor durable.
The offerings from the British-Spanish company Bow-Tie are an improvement on both fronts. They offer economical versions of the traditional beasts of this species, while also adding some novel, and at times perfectly outlandish, mutants to the menagerie.
The silhouettes are quite nice. The patent, velvet, and suede versions all have the luster necessary for nice evening footwear. These shoes are not goodyear welted, so you won't be able to resole them. The silk bows also aren't as nicely shaped in my view as the Belgian Shoes versions.
But the price is right. The slippers go for 185 euros. "Dress shoes" with the silk bows - which includes evening pumps - start at 225 euros. If you want custom embroidery on your velvet slippers, that goes up to 300 euros. They don't have an online store, but you can buy the shoes either in person at one of their stores in Spain, or by emailing them at firstname.lastname@example.org.
PoW, with bows.
Embroidered slippers for pirates.
Patent Belgian with silk bow, on top of my coat.
More traditional Belgians.
More evening shoe options for pirates.
More traditional evening shoes.