Timmy's teacher, Mr. Denzel Crocker, calls for a conference with Timmy's parents for a suspicious show-and-tell project. Not wanting to let his real parents find out, Timmy asks Cosmo and Wanda to pose as his parents. Crocker, who knows that Cosmo and Wanda are fairies, sets up traps for them to prove their existence. However, Principal Waxelplax ends up trapped and gets mad at Crocker in the end.

In order to study about the human body, Cosmo and Wanda shrink Timmy so that he can explore Vicky's human body, but chaos soon ensues.