In large saucepan melt butter over low heat. Add marshmallows and stir until completely melted. Remove from heat.
Add KELLOGG'S® RICE KRISPIES® cereal. Stir until well coated.
Using 1/2-cup measuring cup coated with cooking spray divide warm cereal mixture into portions. Using buttered hands shape each portion into ghost shape. Cool. Decorate with coconut, frosting and/or candies. Best if served the same day.
In microwave-safe bowl heat butter and marshmallows on HIGH for 3 minutes, stirring after 2 minutes. Stir until smooth. Follow steps 2 and 3 above. Microwave cooking times may vary.