You'll need to get all of Smokula's body parts for this. You're going to get the body parts and to do that you take these little dead end paths and fight a boss. Once you beat the boss you get a chest that will drop the body part.
You're also going to need these for the good ending. Wink wink.
Heart - St. Sanders Cemetery
Eye - Hermits Refuge
Liver - Camp FalconBats
Tooth - Direblade Plaza
Brain - Brinelake Dock off of Taco Basura You need to get the Diamond Scale in Bogo mart Direblade Plaza