Ok, maybe it makes you laugh now, but the original idea was to scare the kids. As far as I know, the campaign was effective and a lot of kids got scared of "Mr Yuk".
For all those of you that (like me) have no clue what Mr Yuk was about the story goes like this: it was conceived in 1971 as the mascot for the poison center at the Children's Hospital of Pittsburgh. His image appeared on small green stickers that could be affixed to any container of poisonous substance. The Mr. Yuk stickers were bold and obvious with a phone number for emergencies and the face of a green disgusting "Mr. Yuk"
This is the commercial that bring awareness of what Mr Yuk means... a commercial that was meant to be scary and that I am sure it was at the moment! I find it lovely but I guess it could have scared me 30 years ago.
Thanks to Rob for letting me know about this part of the USA pop culture! :)