"Free Willzyx" ( ) is the thirteenth episode in the ninth season of the animated television series South Park. The 138th overall episode, it originally aired on Comedy Central in the United States on November 30, 2005. In the episode, Kyle, Stan, Cartman and Kenny go to an amusement park and a killer whale, which is being kept in a giant tank there, speaks to them, telling them that it will die if it is not returned to its real home on the moon. They attempt to do this, unaware that the whole thing is just a prank being played on them by workers at the amusement park. The episode parodies the Free Willy film.