Gummy worm ice cubes - infest drinks as they melt. Put the worms in an ice-cube tray, letting them stick out of the top and sprawl over the edges, and fill tray with water; Add cubes to a clear beverage, and watch as kids squirm with delight.
Wrap the Mommy? The Busy Broad: Monster High Party Activities. UPDATE FROM TONI: The mummy wrapping game was too cute. This was a nice game for all ages, even some of the adults got in on the action ;) We played it 3 times I think.