Zebroid

A zebroid (also zedonk, zebra mule, and zebrule) is the offspring of any cross between a zebra and any other equine: essentially, a zebra hybrid. In most cases, the sire is a zebra stallion. Offspring of a donkey sire and zebra dam, called a zebra hinny, or donkra, do exist but are rare. Zebroids have been bred since the 19th century. The extinct quagga was also crossed with horses and donkeys. Charles Darwin noted several zebra hybrids in his works.

http://en.wikipedia.org/wiki/Zebroid