Related Clues:

• Playful knuckle rub
• Unpleasant accompanier of a headlock
• Bit of horseplay involving a headlock
• A real head-scratcher?
• Knuckleheaded act?
• Jocular headlock accompaniment
• Knuckle-to-the-scalp act
• Painful head rub
• What might accompany a headlock
• Knuckle-headed gesture?