Column XVII is the boss of Lost Museum--the sixth adventure.
Clear out the minions every time they spawn. This is a top priority because many have ranged attacks, throw bombs or charge you, so use a fast melee weapon such as a spear or sword to interrupt their attacks to take care of them quick. Dodging constantly with rolls in-between attacks is a life-saver here.
Keep your distance from the boss--using the default gun (the foam gun isn't as good) on the boss is effective. I wouldn't suggest melee weapons on the boss because touching the boss damages you and uses heavy attacks when you're near.
Watch out for the boss' ranged attacks and stay away to avoid a devastating saw attack. This boss also has a charge attack with extended saws on both sides, giving it a wide berth--roll back and out of the way rather than to the side if you find yourself too close.
The achievement pops after defeating the boss.