Another one of their well known songs is "Slyvia's Mother".
He also wrote songs for Johnny Cash ("A Boy Named Sue", "25 Minutes To Go"), Irish Rovers ("The Unicorn"), B0bby Bare ("The Mermaid", "The Winner", "Rosie's Good Eats Cafe"), and was nominated for both a Golden Globe and an Oscar for his song "I'm Checkin' Out" for the movie Postcards from the Edge.
Silverstein also did all the cartooning in his books, which led him to be able to be picky about how his books came out. He would choose the paper, the binding, the print, everything, for his book. Making sure that how the book was made reflected the contents of the book. None of his books are softcovers as he didn't want his work diminished in any way.
On top of all of that, Shel was also a playwright, writing over ten short plays which have been performed many times by several companies in different forms.
It's no secret that Shel Silverstein has been loved by millions of people of all ages. His unique writing style, drawing style, and the combination of things that he accomplished in his life are a pull people can't resist.