He was the leader of the Scourge forces in the continent of Kalimdor, and leader of the Death's Head Cult. He formed an alliance with the Quillboar leader, Charlga Razorflank, and promised her a seat of power in the Scourge. Instead, he plans to use her to enslave her people and enlarge the Scourge numbers.
Amnennar was in charge of the Quillboar in the sacred Quillboar graveyard, Razorfen Downs. His Quillboar cultists protect the outside of Razorfen Downs, while the Scourge protects his throne. Adventurers who seek to defeat him and end the Scourge threat in Kalimdor would have to make their way through Razorfen Downs and defeat Amnennar's cultists. Upon reaching the spire in the center of Razorfen Downs, they would climb to the top and face Amnennar in a final battle.
Although Amnennar is now defeated, the status of his Phylactery is unknown. For now, Amnennar's spirit is still alive, but he is unable to harm others until the time comes for his return.