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, and since there’s been a recent revival of Monster/Halloween cereals, you can still dig up a box of Frankenberry from time to time if you’re lucky.  This cereal was filled with marshmellow goodness.   Delicious!