"Treehouse of Horror XII" was directed by Jim Reardon and co-written by Joel H. Cohen, John Frink, Don Payne and Carolyn Omine. It is the twelfth episode of the annual "Treehouse of Horror" Halloween specials, and, due to Fox's contract with Major League Baseball's World Series, the episode was pushed back to November 6, 2001 on the Fox network, airing six days after Halloween. As with the rest of the Halloween specials, the episode is considered non-canon and falls outside of the show's regular continuity. This was the first Halloween special where the writers did not have "scary names" in the credits. This was due to the terrorist attacks on September 11, after which the staff were "trying to be sensitive", and, according to producer Ian Maxtone-Graham, the Halloween names would all reference the attacks had they been kept. Mike Scully, who worked as showrunner for the episode, stated that the "scary names" were removed because they had also "turned into shameless plugs" for side projects done by "The Simpsons" staff members.