Related Clues:

• Pain in the butt
• Mole, e.g.
• Annoying type
• Gadfly
• Annoying one
• Little brother, maybe
• Yapping dog, e.g.
• D-Con target
• Bug bomb target
• Buttinsky, e.g.
• Spammer, for one
• Mosquito, e.g.
• Unwelcome visitor
• Exterminator's quarry
• Constant interrupter