Shuffleboarding: Mermaidman and Barnacleboy are booked to attend a shuffleboarding tournament, but they can't go because they're laid up in the hospital. So their #1 fans, SpongeBob and Patrick, offer to dress up as the superhero duo and attend in their place. But instead of just attending the shuffleboarding tournament, SpongeBob and Patrick decide that while they're dressed up as Mermaidman and Barnacleboy, why not try a little crime-fighting for one day? Professor Squidward: When Squidward is mistaken for his much more famous rival, Squilliam Fancyson, he is invited to teach a class at the most prestigious music school in Bikini Bottom. Squidward is happy to pretend to be Squilliam if it means he can teach a class of adoring fans-until SpongeBob and Patrick show up and nearly blow his cover.
—NAS