Related Clues:

• Hanger-on
• Worry persistently
• Horse
• Humble horse
• Unwelcome guest
• Bothersome person
• Tiresome sort
• Adamant ant?
• Thorn in one's side
• Annoyer
• Aphid, to a gardener
• Exterminator's target
• Termite, e.g.
• Destructive insect
• Vexatious sort