Complete the quest Nemesis: Dwarfstalker at the Gladiator's Sanctum.
The Wowhead Client is a little application we use to keep our database up to date, and to provide you with some nifty extra functionality on the website!
It serves 2 main purposes:
It maintains a WoW addon called the Wowhead Looter, which collects data as you play the game!
It uploads the collected data to Wowhead in order to keep the database up-to-date!
You can also use it to keep track of your completed quests, recipes, mounts, companion pets, and titles!
So, what are you waiting for? Download the client and get started.