For the mummy... glue a set of googly eyes on the wrapper. Then take white crepe paper and wrap your chocolate bar as many times as you want. I then folded up the edges some to give it that ruffled look.
For the bat... I printed the template out at 60% because I was using smaller chocolate bars. Again, glue a set of googly eyes on. Tape your chocolate bar inside on the middle and use a festive sticker to keep shut.
**TIP** many years ago I learned that you cannot glue googly eyes with a hot glue gun! the black part of the eye melts to the white part and they no longer wiggle. so use tacky glue ;)