Line cookie sheet with wax paper. Melt butter in large saucepan over low heat. Add marshmallows. Cook, stirring constantly, until marshmallows are melted. Remove from heat. Add corn syrup; stir until well blended. Add peanut butter and chocolate chips; stir until chips are melted and mixture is well blended. Add cereal; stir until well coated. Cool slightly. With wet hands, shape mixture into 1 1/2 inch balls; place balls on prepared cookie sheet. Cool completely. Store in cool, dry place. About 4 dozen bites.