"The flesh shaman was created from the blood of the witch, Adria. Because of that, the shaman is able to use magic as she does, channeling the power of blood and fire. Luckily, Adria only has so much blood to shed. And not for much longer."— Lorath Nahr(src)
Flesh Shamans are a variant of Flesh Golem. They are tougher than Flesh Gorgers, but move slower. They attack by hurling bolts of Fire, which deal significant damage from afar. It is advised to kill them first, lest they will resurrect killed Gorgers (note that they can only resurrect Gorgers). On Torment difficulty, the presence of Shamans prevents players from destroying the Gorgers' bodies by all means except Critical Hits.