We start off with a series of pranks by Bart, but Skinner is not impressed.  He tells him about the ultimate prankster but will not tell him what the prank was.  We learn from Willie, that Willie was once the swim coach and Skinner was cool and laid back.  That was until the boy, Andy Hamilton (Jonah Hill), replaced the pool of water with worms and Skinner dove and got trapped for three days.  After that he fired Willie and became the man he is today.  Bart sets off to find Andy and when he does, Lisa eventually convinces him that still living with your mom and doing pranks is kind of lame.  Bart then pulls in a favor from Krusty to get him a job as a errand boy and he eventually gets promoted to TV writer.

Meanwhile, Marge is banned from providing food to her baby group when the parents find out she buys unhealthy foods with trans fats, etc.  Marge makes Homer shop with her at the expensive natural foods store, but the moms are still unhappy to hear Marge used a non-stick tray.  She gives up and hits up the delicious junk food with Homer and they decide to enjoy the junk food themselves while making their kids eat healthy.