Related Clues:

• Nincom-poop
• Sterile pack animal
• Balaam's equine
• Low-level smuggler
• Fatuous fool
• It's often hard to budge
• Grand Canyon transportation
• Horse relative
• TV's Francis, for one
• Slow equine
• It's half ass and sterile
• Surefooted critter
• Mule's dad
• Donkey, in the Southwest
• Mule's cousin