Mr. Yuck - frightening children since 1971.
I just learned (via The Google) that Mr. Yuck was invented in Pittsburgh - so no wonder he was all over the place during my Pennsylvania childhood (and later, when we wore Mr. Yuck stickers while bar-hopping at Penn State for some reason).
Did Mr. Yuck terrorize kids in other parts of the United States - or was he just a Pennsyltucky thing? Leave a comment and let us if you ever had a run-in the the Mean Green One.