Question

hybrid of horse and zebra

Answer 1

hybrid of horse and zebra is "hebra"

Answer 2

When zebras breed with any equine species the offspring is called a zebroid.  More specifically, when a male zebra is breed with a female horse, a zorse is produced, the reverse process produces a hebra, and when a female zebra is breed with a male donkey, a zonkey (also known as a zedonks or donkras) is produced.