The achievement in question involves killing Ghom, Lord of Gluttony (in act III) without getting hit by his gas attack.
Ghom uses this area of effect gas attack in melee a lot, and I don't seem to be able to predict when or how often he will use it. This makes avoiding the attack as a melee character problematic.
Does anyone have a strategy for how to get this achievement as a melee class? Does he have a "tell" that he is about to use his gas? Or do I need to kite him while throwing axes/tornados (which will be incredibly slow). My characters are a Barbarian and a Monk.