This honor goes to Sugar Rice Krinkles, which inflicted incalculable psychic damage upon children of the 1950s with this commercial featuring a goggle-eyed clown proselytizing about carbohydrates. As the YouTube uploader notes, "Ever wondered what would happen if John Wayne Gacy made a cereal ad?"

From the archives: A demonic Mexican clown doll with the power to inspire erotic fantasies.

[Via Anarchist Coloring Book]