The onager is also the name of an early siege weapon.

Onager
Scientific classification
Kingdom: Animalia Phylum: Chordata Class: Mammalia Order: Perissodactyla Family: Equidae Genus: Equus Species: hemionus
Binomial name
Equus hemionus

The Onager (Equus hemionus) is a large mammal belonging to the horse family and native to the deserts of Syria, Iran, India and Tibet. It is sometimes known as the Half Ass or the Asiatic Ass.

Like many other large grazing animals, its range has contracted greatly under the pressures of hunting and habitat loss, and of the four subspecies, one is extinct and two endangered.

Onagers are a little larger than Donkeys at about 290 kilos and 2.1 metres (head-body length), and are a little more horse-like. Some authorities regard one of the four races as a separate species.