Colt is young horse, under one year old
Pony is a horse breed, which if under one year is a colt
Donkey
Zebra
Individual zebras are sometimes trainable. However, the majority of zebras are actually too small to ride. This is of course exacerbated by the fact that they haven’t been selectively bred to be ridden.

Matthew 25:32 ESV / 3 helpful votes
Before him will be gathered all the nations, and he will separate people one from another as a shepherd separates the sheep from the goats.