WOW Quest:Coprous the Defiled (13278)  

Entrance to the Mord'rethar vault is at 63, 62. Coprous has ~107k hp, can be snared and stunned. He melees fairly hard and has an acid spray that hits multiple times for a decent amount of damage (not just in melee range, this seems to be a change from beta). Ranged classes can solo him with caution, melee types will probably want to bring a healer.