Batman became popular soon after his introduction and gained his own comic book title, Batman, in 1940. As the decades progressed, differing interpretations of the character emerged. The late 1960s Batman television series used a camp aesthetic which continued to be associated with the character for years after the show ended. Various creators worked to return the character to his dark roots, culminating in 1986 with The Dark Knight Returns by Frank Miller, followed by Batman: The Killing Joke by Alan Moore, and Arkham Asylum: A Serious House on Serious Earth by Grant Morrison. The success of Warner Bros.' live-action Batman feature films have helped maintain public interest in the character.