Pour cold milk into large bowl; add pudding mixes. Beat with wire whisk 2 minutes. Stir in 3 cups of the whipped topping and 1/2 of the cookies. Spoon into 13 x 9-inch baking dish. Sprinkle with remaining cookies. Refrigerate 1 hour or until ready to serve. Store dessert in refrigerator. Decorate with cookies (tombstones), candy and remaining whipped topping dropped by spoonfuls (ghosts).