It wasn't enough that General Mills had the Monster Cereals line. In 1972, the company introduced two more cereals whose animated namesakes feuded with each other. Instead of classic monsters, Sir Grapefellow & Baron von Redberry were WWI pilots. Scope this ad.
Because of the similarities between these cereals and other "Big G" products, particularly Boo Berry & Franken Berry, Grapefellow and von Redberry didn't last too long. In fact, I have 0 memory of seeing either cereal in my area.