Mwahgann the Unholy, Bloodgorger, is a Unique Blood Clan Shaman found in the Arreat Crater Level 2 in Act III of Diablo III.
In combat, he has Plagued, Poison Enchanted and Illusionist affixes.
A bounty may be offered to kill Mhawgann, in which case the secondary objective is to kill 50 enemies.