Wind Trader Zhareem has asked you to obtain The Heart of Quagmirran. Deliver it to him in Shattrath's Lower City to collect the reward. This quest may only be completed on Heroic difficulty.
I have an unusual request. A certain wealthy individual that I am in contact with off-world is interested in a macabre piece.
Specifically, she wants the heart of Quagmirran.
I hear that the beast has three, but one will suffice for our purposes. As I understand it, you can find Quagmirran resting within a deep pool of water at the Slave Pens.