Boo Berry Breakfast Cereal, 16 oz BoxLimited Edition Boo Berry Cereal. Berry Flavor Frosted Cereal with Monster Marshmallows has 14g of Whole Grain per Serving. To celebrate the 50th anniversary of Monsters Cereal, Boo Berry is bringing down the (haunted) house with a special Monster Mash edition of his blueberry and marshmallow cereal. Get to know..