I would thoroughly enjoy a voo-doo/ bayou theme this year, Buy hats looking like sac dolls, pins could replace your arrows.
As an event, "Voo-doo Zombies" would spawn in place of Baddies and look like a sac version of the baddy, and destroying it would result in a small flow of candy (2 or 3 pieces) that worked like Pyrate Eye patches did.
You guys can run with what to do with the candy, I just thought ya know, graal usually does the stereotypical Graaloween, why not mix it up!