History Literature / CaptainUnderpants

** In Book 5, Ms. Ribble orders the class to copy a poem from the blackboard onto their retirement party cards for her that ends with "Signed, Your Name Here". Looking at the illustrations reveals that the children have literally signed their cards "Your Name Here".

** In the tenth book, the heroes know that [[BigBad Tippy Tinkletrousers]] is their only hope for returning from the Pleistocene epoch, as he is the only one with a time machine. Tippy tells the heroes, "I bet you all want a ride back to the future." [[spoiler:The keyword being future.]]

* BreakoutCharacter: Professor Pippy P. Poopypants, later renamed to Tippy Tinkletrousers. Originally just the VillainOfTheWeek in Book 4, he later became the main villain of both Books 9 & 10, establishing himself as the franchise's most recurring villain, not to mention being the main antagonist of [[WesternAnimation/CaptainUnderpantsTheFirstEpicMovie the first movie]].

* MailorderNovelty: In order to get out of being blackmailed by their principal Mr. Krupp, George and Harold decide their last hope is ordering a 3-D Hypno-Ring from a magazine clipping and hypnotizing Mr. Krupp into doing whatever they want. Much to their surprise, it works [[GoneHorriblyRight better than they intended]].

Not wanting to go through with this, George and Harold order a [[HypnoRay hypnotic ring]] and use it to hypnotize Mr. Krupp into giving them the tape. Then, for laughs, they hypnotize him into believing he is their comic book creation, Captain Underpants. But as a result of [[HypnoFool their inability to handle the ring properly]] (and pouring water over his head, which they weren't supposed to do), Mr. Krupp now transforms into Captain Underpants whenever he hears the sound of fingers snapping, and only turns back with water poured onto his head. George and Harold now have the responsibility to keep Mr. Krupp/Captain Underpants in-line as any snap [[IdiotHero sends him off performing very dangerous and destructive "superheroics"]], though it proves to come in handy in tackling actual evil foes.

Not wanting to go through with this, George and Harold order a [[HypnoRay hypnotic ring]] and use it to hypnotize Mr. Krupp into giving them the tape. Then, for laughs, they hypnotize him into believing he is their comic book creation, Captain Underpants. But as a result of [[HypnoFool their inability to handle the ring properly]] (and pouring water over his head, which they weren't supposed to do), Mr. Krupp now transforms into Captain Underpants whenever he hears the sound of fingers snapping, and only turns back with water poured onto his head. George and Harold now have the responsibility to keep Mr. Krupp/Captain Underpants in-line as any snap [[IdiotHero sends him off performing very dangerous and destructive "superheroics"]].

** Book 12 always blatantly makes fun of the Republican Party (AKA the Grand Old Party, which is often abbreviated to the GOP), by having a council of Grouchy Old People who all watch the Creator/FoxNewsChannel and want to get rid of all the violence in the Captain Underpants books... and their acronym is also GOP. Now, what kid would even ''get'' that?

** The 12th book's second chapter is dedicated to not offending older people (called "grouchy old people", or the "[[FunWithAcronyms GOP]]"), by eliminating words like "poop", and constantly referencing things they like, such as Bob Evans Restaurants, and [[Creator/FoxNewsChannel FOX News]]. The next chapter then goes on to criticize how human evolution led to annoying things like car alarms, leaf blowers, and spray-on hair, and how we built dangerous weapons like nuclear warheads and then had the codes controlled by politicians.

* HereWeGoAgain: The TropeCodifier. It even provides the page image for this trope. The first eleven books all end with George screaming "Oh no!" and Harold screaming this trope's name. The only exception is book 12, which makes sense as it's the last book in the series, ergo they're ''not'' going again.

** In Book 12, the backstory sections at the start of the book chronicle how a chunk of GeniusSerum landed in a grape vienyeard on the planet [[PunnyName Pinot]], which caused the grapes to become self-aware and super-intelligent enough to cause "[[Film/RiseOfThePlanetOfTheApes the Rise of the Planet of the Grapes]]" overnight in protest for being almost harvested into extinction.

** Midway through book eleven, Melvin has a celebration parade where they also play nothing but "Weird Al" songs.
** In the Diaper Baby comic in book eleven, Diaper Baby's family is seen watching ''WesternAnimation/SheepInTheBigCity'' on TV.

* MadnessInducedOmnivore: In "The Terrifying Return of Tippy [=TinkleTrousers=]", when a GangOfBullies see [[MadScientist Tippy TinkleTrousers']] RoBo pants, they freak out and go insane. One of the bullies named Loogie starts eating some dirt and earthworms.