My son, niece, nephew, and myself came up with this idea together, they were looking to do a group costume together for Halloween. We constructed the Whac-A-Mole pinball like game out of a large cardboard box. We painted and glittered the outside and cut out holes in the top and side for head and arm.
The kids wore plastic hard hats and makeup. I made a whack a mole hammer from a plastic rain stick and a large sponge used to wash cars.
We had a great time! Our small town loved it and we still talk about that Halloween.