It looks like Oreo O's cereal [1] is taking a surprisingly sweet page out of the Lucky Charms handbook and adding marshmallows to the mix, so prepare to have your sweet tooth majorly satisfied. The new Mega Stuf Oreo O's Cereal combines the brand's chocolaty, crunchy cereal O's with a generous helping of mini marshmallows, meant to recreate the taste of a classic (or Double Stuf) Oreo cookie. Available exclusively at Walmart, the new cereal will be sold in a standard 10.5-ounce cereal box ($4) or a 28-ounce resealable bag. Check out the cookie-inspired cereal ahead, and get ready to have cookies and milk and marshmallows for breakfast any day of the week.