"Da Echo Isles be Zalazane's ta rule, shadow hunter! Now, and FOREVER!"
Hexmaster Zalazane was the greatest traitor to the Darkspear tribe and self-declared eternal ruler of the Echo Isles. After years of rule over the Darkspear lands, Zalazane's rule was at last ended by an army of Horde champions under the leadership of the shadow hunter Vol'jin, chieftain of the Darkspear.
Before the Darkspears left their island home with Thrall, Zalazane was the best friend of Vol'jin from their childhood, and had done everything together.  However, when the Darkspear trolls returned to the Echo Isles, they were betrayed by Zalazane, the apprentice of Gadrin who had been driven mad by his own power. He used dark voodoo to rob most of the Darkspear trolls of their free will, forcing them to obey him. As his influence spread, his army grew while the number of free Darkspears dwindled. Fearing that all of his people would fall to Zalazane's insidious sorcery, Vol'jin ordered the tribe to abandon the Echo Isles.
The Darkspears and their allies frequently struck at Zalazane's holdings on the Echo Isles, determined to win back the trolls' first home on Kalimdor. But Zalazane had not given up in his efforts to enslave his entire tribe, and so he continued to send his trolls to the mainland in order to drag further Darkspears under his sway. 
Though many trolls and other members of the Horde had journeyed to the Echo Isles to slay him, and a number had even returned with his head, a few days later the magic always wore off and his "head" was revealed to be nothing more than painted rocks, bunches of coconuts, or the head of an enslaved Darkspear troll.
Lands of Mystery
Zalzane's backstory from Lands of Mystery conflicts with the information given in World of Warcraft. The following is information given from Lands of Mystery:
This large troll is draped in black robes and wears a black-and-white, wooden mask reminiscent of both necromancy and voodoo. Wrinkled hands grip a dark quarterstaff with a humanoid skull on the top. Zalazane, in his mid-50s, decided that his people did not need the help of the Orcs in order to succeed. He was further offended when he heard about Thrall’s distrust of arcane magic. With the help of a number of similar-minded trolls — and summoned zombies — Zalazane drove most of his fellow jungle trolls from the Echo Isles. He continues to attack the other trolls of the Darkspear tribe, and his reasoning is unknown. The source of his knowledge of necromantic magic is equally mysterious.
Zalazane’s experiments on the Echo Isles had progressed far further than the Horde ever anticipated, and the trolls created greater undead, such as abominations. The warchief called for a full assault on the Echo Isles before the situation escalated.
This section concerns content exclusive to Wrath of the Lich King.
- Main article: Zalazane's Fall
After years of biding his time and gathering allies, Vol'jin gathered a great army of the Horde and - aided by the elements and the beasts of Durotar - marched on the Echo Isles. The massed army fought through the legions of hexed trolls until they came face-to-face with Zalazane himself. Fleeing across the Isles and gathering his foul magics, Zalazane erected a shield around himself, while he used his magic to turn the Darkspear warriors against their chieftain. Cornered, Zalazane boasted that he was invincible and that no living thing could penetrate his shield...at which point he was greeted by the mocking laughter of the great Loa Bwonsamdi, guardian of the dead.
Damning the sorcerer for usurping his domain, Bwonsamdi brought down the Hexmaster's shield and then exploded him from within, bringing an end once and for all to Zalazane's evil reign of the Echo Isles.
In World of Warcraft
The subject of this section has been removed from World of Warcraft.
Zalazane was a level 10 troll located in the Echo Isles in Durotar. During the Zalazane's Fall event, he was boosted to level 80 as part of the final quest. With the conclusion of the event following the release of Patch 4.0.1, Zalazane and his minions have been removed entirely, in preparation for the Echo Isles becoming the troll start zone in Cataclysm.
This section concerns content exclusive to Cataclysm.
In Cataclysm, there is a region of the Echo Isles known as Zalazane's Fall. After being killed here by Bwonsamdi, the land became tainted.
- / Patch 4.0.1 (12-Oct-2010): Removed.
- Patch 3.3.5 (2010-06-22): Now a part of the Zalazane's Fall event.
Event activated September 7/8, 2010.