At Dell, he illustrated Walt Disney Comics & Stories covers & interiors, New Fun Comics and Animal Comics. It was in the last title he introduced what later became his footnote character, Pogo the Possum along with the other cast members of the Okefenokee swamp. It was also during this time that Walt's association with the fairy tale genre blossomed as Walt created, wrote and illustrated a number of titles for Dell called Fairy Tale Parade, Santa Claus Funnies, Raggedy Ann & Andy, Mother Goose and others..

Gaining popularity quickly, Walt became one of the most talked about cartoonists of the era. His Pogo strips were a lusciously drawn polemic on American society. Humor, political and social commentary were inextricably fused in a style that was both easy to understand and enjoy by children, and yet loaded with high brow gaffs to challenge the intellectual.

There was a downside to Pogo however. Because of the rich political and social commentary, Pogo was frequently removed from the comics pages and sometimes only appeared in the political sections of some newspapers. During an episode in which Kelly spoofed radical senator Joseph McCarthy, one editor banned the strip because "politics has no place on the comics page". Kelly promptly introduced a character into the strip. Miss Sis Boombah who was labeled a red and a political chicken from Providence, the town where the strip was banned.

In the 1960's the strip embraced the social change of the time and had flower children and Russian leaders, it was probably the first comic strip to comment on ecological disaster and man's treatment of the environment.

One particular daily strip featured Pogo talking to Albert stumbling upon a dump in the Okefenokee, stating "We have met the enemy and he is US." The strip was later cited by president Ford for it's frank statement. It also became the poster for earth Day in 1970.

Walt Kelly had a wit and artistic talent matched by few in the history of the comic medium, and copied by many, and when he died on October 18, 1973 from complications due to diabetes, the comics lost a great master whose joyous creation will be remembered for generations.