Stone of the Tides

Stone of the Tides is a quest item only lootable by players on the quest The Curse of the Tides. This is a powerful magical artifact that was once used by the mighty Gurubashi troll empire. It allows the user to control all sorts of water and to summon water elementals. However, it also places a curse on the user which causes them to slowly fade out of existence.

Source
This item drops from Gazban the goblin wizard. To summon Gazban, you must be on the quest The Curse of the Tides and use Catelyn's Blade to destroy the Altar of the Tides. The altar is found deep underwater in Stranglethorn Vale, in the area known as the Vile Reef.

As a Quest Objective

 * The Curse of the Tides - from Catelyn the Blade at the inn in Booty Bay, in Stranglethorn Vale
 * Required:
 * Stone of the Tides
 * Catelyn's Blade (provided)