'Mule' in the Bible

So Absalom's servants did to Amnon exactly what Absalom had instructed. Then all the king's sons got up; each one rode away on his mule and fled.

Then Absalom happened to come across David's men. Now as Absalom was riding on his mule, it went under the branches of a large oak tree. His head got caught in the oak and he was suspended in midair, while the mule he had been riding kept going.