Wanted: The Heart of Quagmirran

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.