Elixir of Ancient Knowledge

Elixir of Ancient Knowledge is a bind to account item that increases the player's experience gained by 300% for 1 hour.

Source
Dropped by the pandarian champion Krol the Blade in Dread Wastes. Additionally, the Archiereus of Flame at Ordon Sanctuary on the Timeless Isle may drop it as well.

Achievements

 * Going To Need A Bigger Bag