Chex cereals were the signature brand of Ralston-Purina's cereal division for years. But did you know there was something called Sugar Chex (formerly Sugar Frosted Chex)? To be honest with you, I didn't even know this existed, as it came and went in about a year or so.
Ralston-Purina obtained a license from Harvey Comics to use Casper and his nefarious uncles, the Ghostly Trio, in this spot.
A few years ago, Ralston sold their cereals, the ones that were still being made anyway, such as the Chex line and Cookie Crisp, to General Mills. Purina, meanwhile, is part of the expanded Nestle company. Go figure.