the Onager was built in 60 B.C
As long as you're talking about the Roman catapult it would be around 50-60BC!
The Onager's scientific name is Equus hemionus, and the Persian subspecies is Equus hermionus onager.
If you mean the ancient catapult, used as a stone-throwing war machine, nobody knows, but you can bet it was a soldier or military engineer.
Onager
I always thought that an onager was a particularly large type of catapult
You turn orange. You get an onager. (catapult)
sprouse
During the Middle Ages (around 1200)
no, it is from a different country (rome) but it is a versian of a catapult
Onager (a wild ass)
The siege weapon was used to defeat enemy defensive fortifications .