Frankenberry was part of a series of “haunted villian/monster” cereals:  Count Chocula and Boo Berry being the other two.

Today, only Count Chocula has survived, but you can still dig up a box of Frankenberry here and there if you’re lucky.  This cereal was filled with marshmellow goodness, as demonstrated by the colorful flying marshmellows right into the cereal bowl.   Delicious!