Cheerios is an American brand of cereal manufactured by General Mills, consisting of pulverized oats. It was first manufactured in 1941 under the name CheeriOats.
In "Chitty Chitty Death Bang", Stewie packs Cheerios when he plans on running away from home.
In "The Son Also Draws", Peter is concerned about a message in his Alpha-Bits until Brian points out that he is eating Cheerios.
In "Mr. Griffin Goes to Washington", Lois dreams about learning that Stewie is an evil genius. The dream ends with Stewie declaring "Cheerio!" and when Lois wakes up, all she can remember is that the dream involves "Stewie and Cheerios".
After being fired from Family Guy, Peter gets an audition to be the caring dad in a Cheerios commercial in "Inside Family Guy".