The Abominable Vegetable Man.
(click ads) Back in the 1950s, before he became the handsome animated icon hanging out with cute little Sprout, the Green Giant wasn't so much jolly as he was fucking scary (see above). Check out this terrifying early black & white TV incarnation (images via). Previous terrifying ad icons: Snuggle. The Balvenie Weenie™. Mr. Opportunity (not really scary, just a douchebag). Mr Min Pornocchio.