Related Clues:

• Onager, for one
• Cart puller
• Silly sort
• Silly fool
• Sure-footed domesticated mammal
• Foolish sort
• Farm animal
• Practically devoid of customers
• Biblical beast
• Balaam's ride
• No longer under consideration
• Bozo
• Item listed in "Thou shalt not covet . . ."
• Obstinate equine
• One with a burden