Shel Silverstein

Sheldon Allan "Shel" Silverstein (September 25, 1930 – May 8/9, 1999), was an American poet, singer-songwriter, cartoonist, screenwriter and author of children's books. He styled himself as Uncle Shelby in his children's books. Translated into more than 30 languages, his books have sold over 20 million copies.

source: Wikipedia