Here are some of my ideas for bosses:
Slippery: -1 reroll at the start of round and after each time you bank.
Tax Collector: Scoring hands now always behave like they're level 1 for this round only.
Scammed: Before banking, -$2. If you can't pay up, you lose! (:<
Twister: At the start of this round and after each time you bank, highlight a certian score category you haven't used yet. If you don't use the highlighted category, X0.5 multiplier.
"Oops": One time you bank (It could be the first, second, third, fourth, or fifth) will automatically score 0 points. You will not know until it's already triggered.
Snowplowing: White dice only give +1 chips when scored (If it's a 1 it won't score at all)
Headstart: x0.5 multi to all times you bank except for the first time you bank.
Nope: Relics will have a 10% to not trigger. (+-multi and +-chips counts as one trigger!)