Bran Flakes is a brand of cereal featured on a TV commercial in the episode "As Seen on TV." The cereal more than likely has bran in it, because of the "Bran" in its name.
Bran Flakes is featured when Old Man Jenkins watches the cereal's commercial on TV. He mistakes SpongeBob for a cereal box from the commercial, even saying "what a nice cereal box" when he meets SpongeBob.
Boxing and Taste
It is unknown what the food tastes like, but it is presumed that it is possibly for older people, and it is identical to normal bran. The Boxing is yellow, and has pictures of the food on it. Nutritional info and other info is on the right side of the box. For taste in "As Seen on TV", it is mentioned to have a bold new taste.