Heigan the Unclean is the second boss of the Plague Quarter of Naxxramas.Commander Eligor Dawnbringer says about him:Observe, Heigan the Unclean. The mastermind behind the plague cauldrons that turned the wilderness of Azeroth into the Plaguelands. It is said that Heigan has rigged the very walls and floors of Naxxramas itself with a vast array of traps, which he can trigger at will.