The original fun poster image was created by the great illustrator Jack Davis a year before his iconic "It's A Mad, Mad, Mad, Mad World" poster, but for some unknown reason, finally not used. Instead it was used for the films publicity, promotional handouts, ("slicks"), newspaper ads, and for several of the foreign posters for the film.
Here's the original, rarely seen (entire) Jack Davis Image:
|click to enlarge|
|and an ad using the entire image|
thanks to Jerry Beck & Mark Newgarden