Bollag, Keeper of the Gates

Bollag, Keeper of the Gates is a massive Aetherial boss. When you obtain the quest Someone on the Inside he will appear next to the lever for the drawbridge in that quest, which is technically part of the Malmouth Outskirts that you get to from the Candle District. If you get the quest Bounty: Keeper of the Gates he will have 4 spawn points in Candle District.