Toon is an abbreviation of "cartoon", probably popularize by the name of the Looney Tunes series of animated shorts by Warner Brothers (though the spelling is different). It became a popular way to refer to a cartoon character in the 1981 Gary K. Wolf novel Who Censored Roger Rabbit? and its film adaptation Who Framed Roger Rabbit. These two works created and established the Toon Noir sub-genre, which features toons and non-toon humans living together, each playing by their own set of physics. The small sub-genre includes Disney's Bonkers and Warner Brothers' Tiny Toon Adventures, Animaniacs and Freakazoid! cartoon series, and more recently, the films Cool World (1992) (where Toons are called "Doodles"), Space Jam (1996), The Adventures of Rocky and Bullwinkle (2000) and Looney Tunes: Back in Action (2003) and also the video game Go! Go! Hypergrind.