The onager, also known as hemione or Asiatic wild ass (Equus hemionus) is a large Equid of the family Equidae (horse family) native to Asia. Unlike most horses, donkeys and even zebras, the onagers can never be domesticated. The onagers are among the fastest mammals, as they can run as fast as 64 km/h (40 mph) to 70 km/h (43 mph).The onager is closely related to the African wild ass, as they both shared the same ancestor.