I actually went to the store with the intention of buying green lemon lime Jello cups to make something similar to these Frankenstein Jello cups from Craft Penguin, but they didn't have any left at my store.
If they had, I probably would have ended up making Jello blob monsters instead like these from Home. Made. Interest.
But alas, no green Jello cups meant cute little ghost pudding cups. A black permanent marker, googley eyes, and a little glue is all you need to transform your vanilla pudding cups into cute Halloween treats.
But if you did get to the sign up sheet early enough to get juice boxes, wrap the juice box with white crepe paper streamers and secure it with tape, then glue on some large goggly eyes and you will be all set. Halloween Mummy Juice Boxes: