|Captain Underpants and the Revolting Revenge of the Radioactive Robo-Boxers|
|Published on||January 15, 2013|
|Published by||Blue Sky (US), Scholastic (US)|
|Captain Underpants and the Terrifying Return of Tippy Tinkletrousers||Captain Underpants and the Tyrannical Retaliation of the Turbo-Toilet 2000|
Tippy Tinkletrousers arrives on an Earth without Captain Underpants. He then vows to change everything back to normal and travels back to the night when Kipper and his friends encounter him. They are then frozen, so they forget everything, thus restoring the flow of time.
He then travels forward in time four years to when George and Harold were all but arrested. The boys then decide to send take their pet pterodactyl Crackers back to the dinosaur age with Sulu, their hamster. The boys then travel back in time, but accidentally take Mr Krupp with them. Eventually, a second Tiny Tippy, slightly younger than the original one, was created.
Tippy and his two miniature clones then travel back to the dinosaur age and pursue the boys and Captain Underpants.The tiny Tippies zap themselves back in time and steals a Goosy-Grow 4000, which transforms Tiny Tippy into the collossal Supa Mega Tippy who betrays Slightly younger tiny Tippy. When Big Tippy attempts to use his nuclear bomb to kill captain Underpants, Supa Mega Tippy zaps himself back in time(with his twin) and kicks Big Tippy away into the Gulf of Mexico. When the bomb explodes, it blows a hige crater and kills the dinosaurs.
The five protagonists and their captor then travel to the African savannas where the boys and their pets gain the trust of some cavemen who inhabit the surrounding jungles. The cavemen are taught English through drawings and subsequently, the boys make the world's first comic book. The Neanderthals, inspired by the book, then set traps for Tippy and defeats him. He then sets off his freeze ray (which has been tampered with by his younger twin so that it could not be turned off), which appears to make Crackers' condition deteriorate and causes the Ice Age (and freezing himself). George and Harold are then transported to the future by Slightly Younger Tiny Tippy where it turns out they are now teachers and Mr Krupp is an old man. Old Mr Krupp was hypnotized into Captain Underpants, and through the boys' willpower, Captain Underpants and his older counterpart beat up Tippy, who afterwards attempts to use a nuclear bomb (Affected by Graviton Levitator) to blow up the galaxy. After that, Crackers and Sulu decide to blow up to save the entire galaxy by sending Tippy and themselves back to the time before the universe existed. The three are then destroyed by Tippy's giant nuclear bomb and the universe is formed, which means the Big Bang Theory is really the Big KA-BLOOSH Theory. And now the reader would know who created the universe, killed the dinosaurs and began the last ice age. It turns out Crackers had laid a brood of eggs and George and Harold decide to take care of them. Suddenly Melvin Sneedly, in his giant squid called the "Supa Squid", appears and captures George, Harold, and Captain Underpants, taking them back to the present.
The end of the book reveals that there will be an upcoming sequel, Captain Underpants and the Terrifying Retaliation of the Turbo Toilet 2000.