PREPARE cake batter as directed on package. Add dry pudding mix; mix well. Spoon evenly into 24 paper-lined muffin cups. Bake as directed on package for cupcakes. Remove to wire racks; cool completely.
BEAT cream cheese, butter, vanilla and food colouring in medium bowl with electric mixer on medium speed until well blended. Gradually add sugar, beating well after each addition.
ARRANGE cupcakes on large serving platter or tray to resemble a monster's head; spread with cream cheese frosting. Use decorating gel to outline the eyes, mouth, scars and hairline on the cupcakes. Fill in the hair with cookie crumbs. Place 2 of the marshmallow halves in centres of eyes; place remaining 4 marshmallow halves in the mouth for teeth. Store in refrigerator.