The Guagga Is a half horse, half zebra. It is now extinct, the last being killed some time in the 1900's.
I think what you mean is Equus quagga. Similar to a zebra, and native to africa, the Quagga was killed by overhunting, for meat and skins. Its pelt was prized for its distinctive markings, and it was shot as a pest because farmers considered it a nuisance.