Use a cookie cutter shaped like a pumpkin and trace 12 pumpkins on orange construction paper, cut them out. Note it is important to try and make these the same size. Then take 11 of the pumpkins and write Trick and on 1 write Treat.
On the Trick pumpkins write a silly thing to do like walk like a spider, or kackle like a witch, or flap your wings like a bat, dance like a fairy, walk like frankenstein and more. Put everything in a plastic witches kettle and have each child draw one out. If they get the treat one then let them choose a treat out of another bucket.
If they get the trick they have to do what it says to earn the treat. Or for additional fun you can continue to make them do additional silly things until they pick out a treat.