Cosmo's brother the top secret spy pays a visit. But when Schnozmo's revealed to be nothing but a con man,/No one will play with Poof, so he runs away to the one place where he's the center of attention: the planet Yugopotamia!
Foop is back! He's escaped from prison and convinced Cosmo and Wanda he's reformed and ready for a playdate with Poof. When Timmy wishes he were the teacher's pet, Poof literally grants his wish and turns him into a guinea pig in Mr. Crocker's class.
When Timmy gripes that being Mom is easier than being a kid, Wanda takes the bait and switches their brains./Frustrated by his inability to catch fairies, Crocker turns his attention to hunting a new magical creature - leprechauns.