Spawn Eggs Donkey, Mule, Skeleton Horse, and Zombie Horse aren't named properly.

Donkey is "Spawn entity.Donkey.name"
Mule is "Spawn entity.Mule.name"
Skeleton Horse is "Spawn entity.SkeletonHorse.name"
Zombie Horse is "Spawn entity.ZombieHorse.name"

EDIT:
As shown in the screenshots, I have a resource pack on. I also checked with no resource packs on and the Spawn Eggs still aren't named properly.