Win a brawl with ten stacks of You Stink! during the Draenor campaign.
To earn this achievement, you will need the help of some bystanders. Or, if you're feeling helpful, you can help others in the arena earn this achievement yourself.
Bring a friend and have them visit Esme Sunshadow (Horde) or Lidiya Peyton (Alliance) in the Brawler's area. These vendors sell Rotten Apples, Rotten Bananas, and Rotten Watermelons, which you can lob at people fighting in the arena. These fruits put the debuff You Stink! on a player when they are hit, which lasts for 20 seconds unless refreshed by another fruit hit.Earning this achievement is just a matter of making sure you have at least ten stacks of You Stink! on you when you land the killing blow on whatever boss you are fighting.