A very sketchy idea that just came to me, and I want to get it down before I forget it. It's an attack that fills you up in the hopes you'll go pop.
Wafer-thin mint
Action - Attack
Each other player gains a copper, putting it into their hand.
Then, each other player reveals their hand. If they have four or more treasures, they must discard two of them.
Still thinking about how much this should cost.