10-year-old Timmy Turner is left alone by his parents with a cruel babysitter, Vicky. After being sent to his room early, beaten and miserable from Vicky's treatment, Timmy throws his Magic 9-Ball against the wall in frustration, releasing a pair of wish-granting fairy godparents named Cosmo and Wanda, who help him retaliate against Vicky.
Having been left alone with a demanding, "injured" Vicky babysitting him and using him as a servant, Timmy wishes up a bunch of clones to do his chores for him. However, when they scare Vicky out of her mind and chaos ensues, Timmy must recover them and wish them away.
While Timmy, Cosmo, and Wanda are playing "Greenbeard," Wanda's wand accidentally ends up with Vicky. She uses Wanda's wand as a prop for her fairy costume at her costume party, and Timmy needs to get back the wand since it is granting Vicky's wishes.
Mr. Crocker realizes that Sparky has magical powers. Eager to use the fairy dog’s powers to fulfill his own wishes, Mr. Crocker hypnotizes Sparky in an attempt to turn him against Timmy.
Timmy has been invited to Tootie's birthday party, but has to take Cosmo and Wanda along because the former has the fairy flu and he cannot leave them unattended. Unfortunately, Cosmo's constant sneezing wreaks havoc upon Tootie, Vicky, the party guests and Timmy himself. Things appear to be at their worst when Wanda becomes sick and begins sneezing as well, which turns Vicky into a fire-breathing dragon, until Timmy and Tootie manage to feed them sauerkraut.
Foop becomes Vicky's anti-fairy godparent. Vicky and Foop terrorize Timmy and the kids of Dimmsdale. Foop tells Vicky that the reason Timmy has thwarted her all these years is because he has fairy godparents. If they can destroy the fairies, no one will be able to stop them.
Timmy, Cosmo, and Wanda are nominated for a fairy award show, but Jorgen Von Strangle, the toughest fairy in the universe, uses his power to persuade the judges not to let the fairies win.
Timmy tries to earn his "Capturing a Mythical Creature" Squirrelly Scout badge; Vicky tortures her scout group.
Crocker kidnaps Timmy's mom because he thinks she's a troll who possesses magic.
For one day in a certain number of years, a fairy godparent has to be "bad", and it is Cosmo's turn to do so. However, he fails miserably at doing so, and Timmy and Wanda enlist Genghis Khan in an attempt to help him. However, this leads to Cosmo attempting to destroy the Earth.
Mr. Crocker becomes a teacher at the Fairy Academy; Poof begins to learn how to talk.
Timmy, his father and the fairies get stuck in a board game created by Cosmo.
Timmy wishes Sparky would get a chance to be heroic, while Dad thinks he can talk to animals.
After making a deal with Dad, Crocker becomes best friends with Dinkleberg
Timmy wishes that Mr. Crocker would disappear, and Mr. Crocker becomes invisible.
To impress a new girl at his school, Timmy wishes that he was several different personalities, one of them being emo.
Fairy Dust has been building up in Timmy's room, so he needs to clear it out before he can make more wishes.
When Cosmo and Wanda bring Timmy back through time to meet their former Godchildren, his interactions with them alter the future.
Crocker tries to program Sparky as an unwitting sleeper agent in his war against Timmy and the fairies.
Poof becomes Mrs. Crocker's fairy godparent, but eventually gets tired after she constantly keeps making wishes. Guest star: Phil LaMarr as Denzel Washington and Announcer
Crocker disguises himself as a Spellementary school teacher to steal magic from the kids and Poof begins to learn how to speak when he goes through "prooferty".
After Mr. Turner forgets the camping supplies for his scouts trip, Timmy tells scary stories to past the time.
On Cosmo and Wanda's anniversary, they go to see their former godkids with Timmy. However, they alter the past and wind up losing their jobs as fairy godparents. Timmy and Sparky must fix the timeline or else they'll never see Cosmo and Wanda again.
Cosmo's reputation as a fairy godparent is at risk when he can't remember if he turned in one of his final tests.
When Dad forgets all of the supplies for the Squirrely Scouts camping trip, Timmy tries to smooth things over with scary stories around a campfire.
Foop replaces Sparky with an Anti-Fairy dog called Anti-Sparky. Guest star: Paul Rugg as the Grim Reaper
Timmy wishes all women away to end Mom's constant nagging.
After deciding she wants to be an actress, Vicky forces Timmy to help her get her first role.
Dad flushes Timmy and the fairies down the toilet.
Timmy tries to inject excitement into his dad's life by wishing it were an action movie.