Large Loot Bag

Work it backwards before you start. One large bag is ten medium loot bags, each of those is ten small ones, and each small one is ten candies. For a solo player that is a lot of Halloween in one item, and the game pays for it with what it calls the best Halloween loot.

So this is where clans pool. Everyone drops their mediums into one large wood box, one person keeps count, and when ten are in, the bag gets upgraded and opened together in the main room. Its text names no further upgrade, so this is the end of the chain. There is nothing bigger to save for, so open it.