MEGA BRANDS INC. - New app offers enhanced building experiencesGeneral Mills, in a partnership with Mega Bloks, is bringing back its free cereal box prizes. Customers can find customizable Mega Bloks cars in select General Mills brands of cereals, including Honey Nut Cheerios, Reeseā€™s Puffs, Cocoa Puffs, Lucky Charms, Golden Grahams, and Cinnamon Toast Crunch. The cars can be customized with the included Hello Kitty and Power Rangers sticker packs. Additionally, the cereal boxes can create a constructable cardboard jump pattern.