Speak with Tabetha in Dustwallow Marsh.
Rumor is that Tabetha, a mage colleague who lives deep in Dustwallow Marsh, has a bone to pick with a certain sand troll in Zul'Farrak. If you speak with Tabetha she can tell you more.
And bring some friends with you, [player]. If Tabetha has you go to Zul'Farrak then you're not going to want to go alone.
You will find Tabetha's cottage west of Theramore, and just north of the Stonemaul Ruin.