The Overproof of the Pudding

 is a limited time side questline released on December 19, 2015, along with the Winter 2015 Event's Act 2. To start the quest, the player had to complete Once In Royal Quimby's City Pt. 5, Holiday Mystery Meat Pt. 2 and No Man is a Fortress Pt. 1.

Quests
* see the detailed list of the tasks to upgrade the "Moonshine Shack" here