Azaloth

The pit lord Azaloth is held prisoner by Illidan's blood elves at the ruins of Karabor at the Black Temple. He proved too strong to be used as a demon hunter initiate's exercise and is kept banished by blood elf warlocks. Players free him by killing a Sunfury warlock and getting a scroll of unbanish quest item. Azaloth does drop loot.

A Necessary Distraction
In, you need to find a Scroll of Demonic Unbanishing from Sunfury summoners and warlocks. When Azaloth is freed from his banishment, he will begin raging around and cleave down few groups of Sunfury elves, till the Illidari demon hunter Alandien comes and brings him down.