Line cookie sheets with waxed paper. In large saucepan, melt margarine and marshmallows over low heat, stirring until smooth. Remove from heat. Stir in food color until well blended. Add cereal; stir until well coated.
Spray 1/3 cup measuring cup with nonstick cooking spray. Place rounded 1/3 cupfuls of mixture onto waxed paper-lined cookie sheets. Shape into 3-inch rounds, about 1/2 inch thick.
Decorate rounds with icing, licorice and candy corn to make jack-o'-lantern faces. Flatten gumdrops; shape into leaves and eyes. Attach to top of jack-o'-lanterns with icing. Place on waxed paper; let stand about 10 minutes or until firm.