"As long as there's one smoldering ember on the barbecue of justice, you can still cook a mighty steak...of victory!"
— The Crimson Chin
The Big Superhero Wish! is the fourteenth episode of Season 4. It is a half hour special.
When Timmy needs to be saved from Francis, nobody is his hero, to save him. So he wishes for a world of heroes like his Crimson Chin comic book. Now, all of his classmates have super powers. Some are heroes and others are super villains. When his fairies are trapped, Timmy wishes for "no more super heroes, when Nega-chin covers his mouth so only super powered bad guys remain. How will "regular" weak people defeat the super-villains?
Next day, Timmy is walking to school when Francis threatens him. He needs a hero to save him, but nobody saves him. Even the fire-fighters pass him to save a cat instead of saving him. Later, inside Dimmsdale Elementary School, he opens his locker. Suddenly, a wave of F's falls out of his locker and floods the school hallway. Mr. Crocker rows nearby on a rowboat, and says that he had given Timmy every future F until college. He evilly laughs. As Timmy begins to sink beneath the F's, he begs the school janitor for help. Later, Timmy returns home, when Vicky welcomes him with a breakfast: she gaves him a sandwich, but when Timmy asks for milk, Vicky squashes a milk carton on his head. Suddenly, a milkman appears and feeds Cosmo in his cat form, instead of saving Timmy. When Timmy asks for help, and nobody is his hero to help him, he wishes for a world of heroes same as the Crimson Chin comic book. At that moment, The Earth is transformed into a comic book called "Action Planet, Issue One". The Turner's House becomes metallic and the sky is filled with print dots. Timmy's alarm clock awakens him, and he realizes he is late for school. A rocket appears from his chin and blasts him off to school, while Cosmo and Wanda, disguised as Chin-Hounds, follow. Inside Timmy's room, Short-Fuse watches Timmy and completes his mission by reporting and telling Nega-Chin that it is time to begin their plan. Nega-Chin remarks on the quickness of this development, saying "That was short!", causing Short-Fuse to explode in anger. (Literally, because he's an alarm clock with a fuse on his head that lights when he's angry.) Timmy flies to his school, which has become a floating super school, and sees that all his classmates have superpowers as well. Chester McBadbat has become Matter Muncher Lad with the ability to bite through anything, Elmer is the Bouncing Boil and able to bounce around on his giant boil. Sanjay is able to fly around and is called "The Sonic Youth", and also has the ability to emit a powerful sonic scream. A.J. has become Professor A.J., his powerful mind has the ability to project force fields and read minds. Trixie Tang is Wonder Gal, who is "super fast, super strong, and super popular", whereas Veronica has become Hawk Gal who is merely able to "fly at speeds between 20 and 30 miles per hour".
As Timmy arrives at school, he soon realizes that not everyone became a hero, as he is immediately attacked by Francis, who has become Bull-E. According to him, the E is there because it is the second letter in death. Bull-E thrashes Timmy and his super friends until the Crimson Chin comes along. The Chin strangely decides to use a teleport gun that sends Bull-E away to an unknown location. The Crimson Chin's eyes are also uncharacteristically glowing red. The Crimson Chin asks if there are any other of Cleft's enemies to deal with, when Vicky comes along and reveals that she has become The Baby Shredder. She has sharp claws, a razor sharp tongue, and a strict 7 o clock curfew that will "tear you apart". Mr. Crocker also arrives, becoming Doctor Crocktopus, his four powerful tentacles have the ability to give four failing grades at the same time. While Crocktopus and the Baby Shredder attack, the Crimson Chin stops them and warps them away using his teleport gun. Timmy thanks the Crimson Chin for his help.
Inside a real swamp, the "Crimson Chin" presses a remote and a lair shaped like the Nega-Chin's head emerges from the swamp waters. The Chin flies inside and frees Bull-E, the Baby Shredder, and Doctor Crocktopus, who had all been teleported there by Nega-Chin, who reveals himself to them, having been disguised as the Crimson Chin all along. The real Crimson Chin is currently locked up in a cage in Nega-Chin's lair. At the super school, Timmy's classmates assemble when Principal Waxelplax, as a cat-themed superheroine, alert them of an attack by the villains. At Nega-Chin's lair, Short-Fuse frees the Crimson Chin.
Back in Dimmsdale, Timmy and the other superheroes arrive to see the town mostly deserted, and believe the other superheroes must have won. Nega-Chin shows up and reveals it was a trap, as Timmy's arch enemies were hiding behind Mike the Evil Living Building. Clefto and Ace (Cosmo and Wanda) try to take on Mike the Evil Living Building, which Clefto attempts by urinating on him, but he gets kicked away before he and do so. Timmy then attempts to wish the heroes and villains away, but the wish ends up erasing only the superheroes due to Nega-Chin halting him before he could say "villians."
The now non-supers take refuge in Timmy's treehouse can use the help of real superheroes, the fire fighter, janitor, and milk man that had failed to help out Timmy earlier, although he is reluctant to accept their help, due to their earlier inaction. The Chin then insists that just because somebody doesn't wear a costume doesn't make them not a hero. The three humans promise to help this time.
At Nega-Chin's Lair, They reached there with the milkman, firefighter and janitor and The Nega-Chin leaves to the restroom to go take a "bath of evil". The villains and normal people to battle, though the villains manage to knock them around a bit, they begin to use teamwork to take down their foes. The janitor mops the floor wet, causing Bull-E to slip and fly out a window, which Elmer closes shut and remarks that manipulating windows are his normal powers. Timmy realizes they all have normal powers they can use. Chester, A.J., Sanjay, and Elmer are then captured by Doctor Crocktopus' arms. Dr Crocktopus then creates a fiery F on the ground, but the fire lady extinguishes it with a fire extinguisher. The fire fighter lady then throws her axe which frees the trapped and severs Crocker's mechanical arms (one of which, according to Crocker, isn't mechanical) and he faints, falling into the Janitor's trash can. The Baby Shredder charges at Timmy and Elmer with her claws, but they move out the way while the milk man blinds her with milk shot from a cow's utter (while also reluctantly saying to Vicky to prepare for "udder defeat"), and she gets stuck in the door. Elmer uses a hammer to bend her claws on the other side of the door, entrapping her, and Chester bites her ankle, saying that he's always wanted to do that, even though his teeth are no longer super.
Nega-Chin emerges from the bathroom, muttering about the lack of hot water in the, when he sees that the ordinary people have defeated the villains. Nega-Chin tries to use his nega-vision to cut through the Crimson Chin and Timmy, but he grabs Timmy and flies out of the way, the beam then hits Cosmo and Wanda's anti-magic bubble prison behind them and they are freed. Timmy quickly wishes everything back to normal, and himself, the Chin, Cosmo and Wanda, and Nega-Chin into a Crimson Chin comic book. Mr. Crocker, Vicky, and Francis are changed back to their normal selves along with the rest of the world (Crocker saying "oh, poopy!" to this). In Chincinnati, The Chin regains his super powers and becomes "Chintastic" once again, the Nega-Chin curses in despair that he was beaten by ordinary people and doesn't understand how that was possible, but Timmy remarks that being normal does not mean that you are powerless, and in fact, ordinary people control his existence. The Nega-Chin refuses to believe this, but the Crimson Chin points out that it is true, by pointing at a picture of the "real life" author of the Crimson Chin's comic books, and that as long as the writers want the Crimson Chin to win, he will. The Chin then breaks free of his ensnarement and flees the comic; Timmy is about to go after him, but Crimson Chin says to let him go, because evil will never triumph over good. Timmy, he and his fairies slowly back pedal out of the comic frame.
At this same moment, the Crimson Chin Author is trying to come up with a line for the Crimson Chin to say, but then he sees the Nega-Chin, before telling his mother "I'm going out!", his mother tells him not to come back until he gives her grandchildren.