Archmage Lan'dalock in Dalaran wants you to return with the Prophet's Enchanted Tiki. This quest may only be completed on Heroic difficulty.
Drak'Tharon Keep once stood as a proud bastion of the Drakkari nation. Now it is nothing more than a stepping stone for the Lich King in his fight to put an end to Zul'Drak and steal the powers of the troll gods.
But if we were to eliminate their leader, the Prophet Tharon'ja, perhaps we could stop the flow of Scourge troll reinforcements. At the very least this would give the Argent Crusade in Zul'Drak one less thing to worry about.
Return to me with his tiki so I will know the prophet is slain.