Divide the class into a few teams and have them each choose a "mummy" and a wrapper. The wrapper has to wrap the mummy head to toe using a roll of toilet paper. The goal is to be the first team to finish by using up the entire roll of paper. It's really fun and pretty hilarious although it does take a little while, so you may want to start with a roll that is half empty! The kids can also take turns being the wrapper. The roll does sometime break as it is only toilet paper and the kids can get kind of excited, so I just had them tuck in the ends to the loops already made.
Another mummy idea is to use marshmallows and wrap them in Fruit by the Foot. Then take some frosting and make little eyes and then eat.
Bingo is also a favorite (but it also takes forever). The kids can use candy corns as their markers and then eat them.
What about maybe a coloring contest? Print out a picture of something festive and see who can do the best job coloring it. You'd have to find an impartial judge or you room moms could pick the top 3, as long as they were anonymous, and then the class could vote on the best.
You could do a continuing story...(you might want to start a couple so the kids aren't waiting too long to write something and just pass them all around on different colored papers or something) but start with some sort of spooky sentence that the class helps create. Then the next person writes a follow up sentence and then folds over the first sentence so only their sentence can be seen...and passes it on. Then the next person writes something and folds over the sentence above and passes it on. It's sort of like a written version of telephone.