( EW.com ) -- Late last year , news broke that The Simpsons were going to turn a decades-old spec script written by Judd Apatow into an episode . As it turns out , the A-list comedy writer-director-producer is collaborating with the animated series in front of the microphone as well . EW has learned that a different episode â€ ” which was already known to boast Will Arnett as a guest star â€ ” features the voices of Apatow , frequent collaborators Leslie Mann , Paul Rudd , and Seth Rogen , plus Channing Tatum and ... Judas Priest frontman Rob Halford . EW : 'The Simpsons ' : Daniel Radcliffe to guest . Fed up with movie theaters , Homer is taught by Bart how to illegally download films , and he starts screening them in his backyard for folks in Springfield . `` Even though Homer is stealing , he 's doing it for the community , he 's doing it out of the goodness of his heart , '' says executive producer Matt Selman . Alas , an overzealous FBI director in charge of anti-piracy ( Arnett ) does n't quite see it that way and sets his sights on Homer . How do our celebrity guests fit into the plot ? One of the movies that Homer shows is a This is 40-esque Apatow dramedy titled Life is Funny that stars Mann and Rudd , who joined forces in Knocked Up and This is 40 . Halford winds up singing a parody of the Judas Priest classic `` Breaking The Law '' in an effort to nab Homer , while Apatow testifies against our patriarch `` with a hilarious , self-important speech about Hollywood people , '' says Selman . Another Knocked Up star , Rogen , has a cameo role as himself , as does Tatum . `` Channing Tatum loves to do surprise twists in movies , a la This is the End , '' hints Selman , `` and he has a surprise twist in this one too . '' EW : 'The Simpsons ' to join forces with 'Futurama ' for crossover episode . That 's not the end of the movie-based madness . At the very end of the episode , adds Selman , `` there is a crazy twist where Rudd returns in a super meta thing that people may or may not understand . '' The Apatow & Friends showcase , which is titled `` Steal This Episode , '' is slated to air in January . It marks a return visit to Springfield for Rudd and Rogen : Rudd guested in a season 22 episode and Rogen co-wrote the season 21 premiere and voiced a character . See the original story at EW.com . CLICK HERE to Try 2 RISK FREE issues of Entertainment Weekly . © 2011 Entertainment Weekly and Time Inc. All rights reserved .
Several celeb voices will be featured on `` The Simpsons '' Judd Apatow and several of his collaborators will appear . The episode is slated to air in January .