Divide vanilla pudding among pie crusts. For each pie, cut three grapes in half and place cut side down in pudding. Cut six 3/4-inch circles from fruit leather. Press fruit leather onto uncut grapes. Using a dab of black icing, "glue" the icing eyes to the fruit leather. Using the writing tip, pipe eyelashes above the eyes with black icing. Place grape eyes and Gummy Worms in each piecrust.
Before serving to a child age or younger, cut grapes into small pieces, and remove icing eyes and Gummy Worms.