'The Itchem and Scratchem Show' makes its debut on an all-new episode of The Simpsons this Sunday, December 8, at 7/8c, only on Fox. Principal Skinner promises the students that the best behaved among them can take a ride in a submarine. When Skinner gives all the kids a clean slate, Bart believes even his own past indiscretions will be forgotten if he doesn't get into any more trouble. Meanwhile Lisa tries to help a cash-poor Krusty to turn things around by suggesting he sell the foreign rights to his shows in Yellow Subterfuge. Take a look at this special sneak peek before tuning in tomorrow, which introduces two ganja toking critters who'll inhale just about anything.