Lena the Hyena was a character in the comic strip Li'l Abner.
She was meant to be the world's ugliest woman (or at least in Lower Slobbovia) and the artist Al Capp never depicted her, presumably because he thought he could never do her justice. Anyone who saw her face in the strip went instantly insane.
Due to public pressure because so many people wanted to know what she looked like, Al held a contest to find out. The judges included Salvador Dali, Boris Karloff and Frank Sinatra and many professional cartoonists including Carl Barks and Jack Cole entered but the contest was won by the relatively unknown Basil Wolverton. The winning picture was then published on the cover of the magazine Life.
The character made a cameo appearance in the film Who Framed Roger Rabbit, chasing Bob Hoskins around Toon Town.