1. Melt the butter in a large saucepan over low heat. Add the marshmallows and stir until completely melted and smooth. Remove from heat and stir in a few drops of pink food coloring until desired brain-like color is achieved. Add the Rice Bubbles cereal and stir until well coated. Lightly grease your plastic brain mold (if using). Press the marshmallow mixture firmly into the mold, or shape by hand into brain-like forms. Let cool completely at room temperature or in the refrigerator. Once set, carefully remove from the mold. Decorate with red gel icing to create a gruesome ‘bloody’ effect. Serve and scare!