|—Captain Underpants' catchphrase|
Similar to his alter ego, Captain Underpants is a bald, overweight man. He has a pear-shaped body and a small piggy nose. Captain Underpants has green eyes, as shown by the appearance of Mr. Krupp's Dummy.
His attire is nothing more than a pair of white briefs and a red polka-dotted cape fashioned from curtains. In the book series and movie, Captain Underpants' cape always looks the same, while in the Netflix series, it changes design depending on what type of fabric he uses for it. He will not fight without his cape, so it is very important he wears one.
Captain Underpants is a superhero written by George Beard and Harold Hutchins in their comics. After the two hypnotize their principal, they decide to have a little fun and goof around with the Hypno-Ring. They hypnotize Benjamin Krupp into thinking he is a chicken, then a monkey, then Captain Underpants. Unfortunately for them, Mr. Krupp thinks he truly is Captain Underpants and jumps out the window to fight crime.
His first stop is at a bank. The two robbers are paralyzed with laughter upon seeing him and are promptly arrested. Captain Underpants also irritates a police officer who tries to arrest him, but he is saved by George and Harold. The three also witness two robots stealing a large crystal. Captain Underpants tries to stop them, but his cape gets caught on their van. He is dragged to an old abandoned warehouse, with George and Harold clinging to his feet. There, they meet Doctor Diaper, who has Captain Underpants tied up, but George and Harold escape. Dr. Diaper begins powering up his machine to take over the world. George and Harold destroy the robots and free Captain Underpants. Dr. Diaper attempts to stop them, but Captain Underpants sling-shots his underwear over Dr. Diaper's face, rendering him defenseless.
All four escape the explosion of the Laser-Matic 2000 unharmed. Captain Underpants then tapes Dr. Diaper to a flagpole at the police station. Upon arriving at school, George and Harold have Captain Underpants get dressed into Mr. Krupp's clothes and attempt to turn him back into Mr. Krupp, but they have lost the manual and are unsure how to do so. In desperation, George dumps water on the hero's head, turning him back into Mr. Krupp. However, as a result, the Captain Underpants personality remains and Mr. Krupp will turn back into the superhero at a snap of a finger.
George and Harold accidentally unleash the Talking Toilets on the school and get cornered by them. Amongst the chaos, Tara Ribble snaps her fingers, turning Krupp into Captain Underpants. Captain Underpants then runs around town, collecting as much underwear as possible. Upon his return to the school, he discovers that flinging underwear into the Toilets' mouths does nothing. After George and Harold realize they can use the cafeteria food to stop the toilets, Captain Underpants uses the last pair of underwear to sling-shot it into The Talking Toilets' mouths.
When The Turbo Toilet 2000 appears, Captain Underpants attempts to fight it. Unfortunately, he gets eaten before landing a single hit. The toilet water inside turns him back into Mr. Krupp.
Captain Underpants and the Invasion of the Incredibly Naughty Cafeteria Ladies from Outer Space (and the Subsequent Assault of the Equally Evil Lunchroom Zombie Nerds)
After George and Harold convince Mr. Krupp to investigate the strange lunch ladies, he discovers the truth about the lunchroom Evil Zombie Nerds. However, before he can do anything, Jennifer snaps her fingers. Captain Underpants then runs away screaming before trying to buy a cheeseburger at a local shoestore, implying that he found George and Harold's fight with Zorx, Klax, and Jennifer offensive (as indicated by the warning from the Incredibly Graphic Violence Chapter part 1).
When he returns, George and Harold get mad at him for leaving. However, their anger disappears the moment the alien lunch ladies order the Zombie Nerds to hunt down George, Harold, and Captain Underpants. They run onto the roof and sneak into the aliens' space ship, where they find strange juice cartons (most notably Extra-Strength Super Power Juice). After George and Harold sabotage the ship, Captain Underpants tells the boys his plan to swing to safety with toilet paper. When they question if it will hold, he reminds them it's two-ply, therefore it has to work. George and Harold grab on to his cape to try and stop him, but this results in them all being pulled out.
As expected, the toilet paper does not hold. However, George and Harold's weight balances out the cape, causing it to function as a parachute and allow them to fall down slowly. As they near the school roof, Captain Underpants is grabbed by the Deliriously Dangerous Death-defying Dandelion of Doom while George and Harold land on the school roof. Hoping to save him, they reluctantly decide to give him Extra-Strength Super Power Juice. The next time the Dandelion of Doom swings him by, he uses his newly obtained superpowers to easily defeat the garden beast.
For the remainder of the book, Captain Underpants stands by as George and Harold cure the Zombie Nerds. At the very end, they splash water on his face to turn him back into Mr. Krupp as soon as everyone is cured. From now on when anyone snaps their fingers, Mr. Krupp becomes Captain Underpants and has super powers. While Mr. Krupp cannot use his super powers because he doesn't realize he has them.
Professor Poopypants shrinks the school with the Shrinky-Pig 2000 and forces everyone to change their names. George (now renamed Fluffy) and Harold (now renamed Chessball) find Mr. Krupp (now renamed Mr. Pottybiscuits) and snap their fingers. Mr. Pottybiscuits transforms into Captain Underpants. However, Chessball informs him he has been renamed Buttercup Chickenfanny. Captain Underpants is upset by his new name and refuses to adopt it, as he doesn't take orders from anyone. At that point, Fluffy orders him to bring them to the Goosy-Grow 4000 and he (ironically) obeys. On his way back, Captain Underpants has shrunk yet again so that nobody can see him. He finally gets the Goosey-Grow 4000 to Fluffy and Cheeseball and tries to unshrink the school, but he gets thrown off. Fluffy and Cheeseball use the Goosey-Grow 4000 to make a large paper airplane to fly on. Minature Captain Underpants then toilets the paper airplane to the ground. As a steamroller comes by, Captain Underpants carries the boys away. Afterwards, Fluffy uses the Goosey-Grow 4000 to make Captain Underpants big enough to fight Professor Poopypants. When the Professor is defeated, George and Harold restore everything (including the Captain) to its normal size. They force Captain Underpants to redress and spray him with a hose, turning him back into Mr. Krupp.
After getting Fs and Gs as their grades due to the wedding disaster, George and Harold try to hypnotize Ms. Ribble to change their grades back. While they're at it, they command her not to try to destroy Captain Underpants or become a supervillain. However, George and Harold fail to realize the 3D Hypno-Ring has the opposite effect on women. After becoming the wicked Wedgie Woman, Mrs. Ribble goes to the boys' treehouse to demand they give information on Captain Underpants. During a little fight, she gets some Ultra-Strength Superpower Juice on her hair, giving it super powers and enhancing her intellect. She uses this newfound intelligence to build Robo-George and The Harold 2000, who are designed to hunt down Captain Underpants and spray starch him so that he loses his powers.
After a kickball game gone wrong, Mr. Krupp snaps his fingers after the robots ignore his orders. This causes him to turn into Captain Underpants. Immediately, the robots chase after him. Captain Underpants mistakes the robots for George and Harold and remarks about how happy he is that the boys have superpowers. They promptly use Spray-starch on him. He is hung by his underwear on a large pole and left trapped. After George and Harold escape, they realize he still has his powers; he just believes that they've been taken away because of their comics. They try to tell him this, but he won't change his view. After failing to find any fabric softener, George and Harold make a comic and force Captain Underpants to read it. The comic explains that as a child, Captain Underpants swallowed a magic amulet that allowed him to instantly fight off the powers of starch. He then returns to his superstate after attempting to comment on the metaphor of the amulet. With his powers restored, he destroys Robo-George and Robo-Harold.
When the Wedgie Woman is defeated, George and Harold tell Captain Underpants to go to the school, get dressed, and wash his face. He does that and turns into Mr. Krupp again.
Captain Underpants and the Big Bad Battle of the Bionic Booger Boy - Part 1: The Night of the Nasty Nostril Nuggets
He loses his cape and gets to safety. Ms. Anthrope then kisses Captain Underpants as thanks, causing him to turn back into Mr. Krupp. Mr. Krupp then gets eaten by the Bionic Booger Boy.
Captain Underpants and the Big, Bad Battle of the Bionic Booger Boy - Part 2: The Revenge of the Ridiculous Robo-Boogers
When Mr. Melvin snaps his fingers, Kruppy the Kid turns into Captain Underpants (or more accurately, Captain Kruppy the Underpants Kid). Mr. Melvin then makes George and Harold tell him everything about Captain Underpants.
Meanwhile, Captain Kruppy helps a little girl get her cat out of a tree (getting two old ladies stuck in the tree in the process), breaks gangsters' skateboards, and deflates the Purple Dragon Sing-Along Friends ball (ruining their biggest game of the year).
Mr. Melvin makes George and Harold call for Captain Kruppy, so they can switch bodies. They do, and Captain Underpants flies out the window... only to fall three stories to the ground. He thinks he forgot how to fly, but he then finds out that his powers were transferred to Melvin Sneedly's body. Carl, Trixie, and Frankenbooger grab onto a spaceship that was examining Uranus, where the robot and the toilets from Book 2 are. They hang onto the spaceship as the spaceship goes back to Earth. Once on Earth, they start destroying the spaceship center.
Captain Underpants, despite the fact that he doesn't have superpowers, decides to go after the Robo-Boogers. George and Harold follow him. They originally lose to the Robo-Boogers, but they figure out that the Robo-Boogers die when they come into contact with oranges (the vitamin C in the oranges counteracts against the cold and flu viruses that made the boogers evil). This way, they beat Carl, but Trixie and Frankenbooger become more cautious and dodge the oranges.
Captain Underpants defeats the Robo-Boogers by standing on top of John's House of Toilets (the top of the store is a giant toilet lid) and doing an annoying dance. The Robo-Boogers start to climb up the building, when they get hit by a well-placed Squishy. Soon George and Harold have to answer questions for Ingrid Ashley and her crew, but Melvin comes and lies to the Eyewitness News crew, saying he beat the Robo-Boogers with his super-powers. While Big Melvin tries to make Captain Underpants bow down to him, George and Harold sneak back to the school. George and Harold then return with the Combine-o-Tron 2000 & Forgetchamacallit-2000. They then use the Combine-O-Tron 2000 on Big Melvin and Captain Underpants, giving Captain Underpants his super powers again. They then erase the memories of the news crew and the TV audience with the Forgetchamacallit 2000 As George and Harold leave back to their treehouse, they use a water fountain to splash water on Captain Underpants' face and return him to his Kruppy old self (without getting dress)
When George, Harold, and Crackers snap their fingers to defeat their evil twins and Giant-Evil Sulu, Captain Underpants ties Nice Benjamin Krupp, Evil George Beard, and Evil Harold Hutchins in a bind with rope. However, it immediately rains, turning Captain Underpants into Mr Krupp and Nice Mr. Krupp into Captain Blunderpants. Confused by his current whereabouts, Mr. Krupp leaves to search for his house.
As George and Harold are being taken away by Officer Wiggly and the Police Chief the cops stop by Mr. Krupp's house where he is seen taking out the trash after cleaning the house from the wet soggy toilet paper, The Cops rush and handcuff a confused Mr. Krupp. After their court date, George, Harold, and Mr. Krupp aka Captain Underpants were arrested and were sent to jail. George and Harold are sent to the Juvenile Hall while Mr. Krupp was sent to the Piqua State Penitentiary One autumn afternoon, Tippy Tinkletrousers (who is also a prisoner from the fourth book) is tasked to build a statue of Warden Gordon Bordon Schmorden who is the chief jailer of the prison, Tippy does the task but instead builds "a giant robot suit". Krupp notices Tippy and he remembers and confronts him for what happened the last time when he shrunk the school and make everyone change their names. However, Krupp does not remember that he as Captain Underpants was the one to put a stop to Tippy's reign of terror that day.
On the day Tippy presents his robot suit to Gordon Shmorden, he reveals his work and climbs on to the suit and freezes everyone in his way (the same suit used at the very end of the eighth book). Tippy then grabs Mr. Krupp and forces him to spill the information of Captain Underpants and to give him the information of George and Harold whereabouts Tippy soon finds George and Harold and puts Mr. Krupp down, wanting information about Captain Underpants. Krupp picks on them, telling them they are in a lot of trouble. Seeing that they are in danger of Tippy plotting his revenge, George and Harold act fast and snap their fingers at Mr. Krupp, who turns into Captain Underpants. Tippy then realizes that Mr. Krupp was Captain Underpants all along and chases him while trying to freeze with The Freezy-Beam 4000 at him Soon, he accidentally freezes his robotic legs and as a last resort, time travels to five years into the past. Captain Underpants flies down in confusion, wondering where he might have gone.
It then goes back to when Kipper and his friends were running out of the school. At this point, Tippy and his Robo Pants appear. Due to Tippy's dialogue with, Kipper and his friends while it was still dark, they mistakenly thought that it's the haunted pants of The Wedgie Magee and become insane. Tippy then travels four years into the future. Unbeknownst to Tippy, his actions led to Kipper Krupp Loogie Tope Bugg Usalowzgi and Finkstein Noviz being sent to a mental health institute and the police to immediately suspect Mr. Krupp for what happened to the sixth graders (in both the original and changed timeline, Mr. Krupp was unintentionally beaten up by his own nephew, Kipper, and his friends while escaping from the school due to a blackout). The Cops show up and blame Mr. Krupp. This eventually led to Mr. Krupp being fired which means in a few years he would not be hypnotized by the 3D Hypno Ring into becoming Captain Underpants.
Atfer changed the time line back to normal George and Harold notice that Mr. Krupp is also there with them hanging on a tree branch calling for help. Harold goes out to grab his hand, but then Tippy kicks the tree. The five are then knocked down and the Purple Potty is then destroyed. George, Harold, and Mr. Krupp are saved by Crackers and Sulu. However, Mr. Krupp does not know this yet. Then, Tippy threatens to kill George and Harold. So the boys quickly snap their fingers at Mr. Krupp, turning him into Captain Underpants
later Big Tippy then falls into a lake, turning Captain Underpants back into Mr. Krupp. Just then, Supa-Mega Tippy Tinkletrousers and Slightly Younger Tiny Tippy Tinkletrousers arrive. Tippy then tells the two that Captain Underpants' weakness is water. However then, Supa Mega Tippy then tells Big Tippy that HE is going to destroy Captain Underpants, not him. Out of anger, Big Tippy sets off his nuclear bomb. But Supa Mega Tippy kicks him into another part of the world. However, the bomb still blows up, killing the all the dinosaurs.
The six then travel to a time about 200,000 years ago, when Caveman first existed. Supa Mega Tippy then captures George, Harold, Crackers, and Sulu. Sulu then tears a hole through Tippy's robotic hands, and the four friends fly off, promising Mr. Krupp that they'll come back for him. Tippy then holds Mr. Krupp hostage under a waterfall until further notice.later George, Harold, Crackers, Sulu, and the cavemen run over to Mr. Krupp to free him. However, the ice encases over everyone and freezes them. When all hope seems lost, Tippy, now 200 feet tall, grabs everyone with his robotic hands. Then, George and Harold snap their fingers again, turning Mr. Krupp back into Captain Underpants. Captain Underpants rips off Tippy's robotic pants, leaving him standing there in his boxers. Using the pants as a net, Captain Underpants, George, Harold, Crackers, and Sulu take to cave people over to France, giving them a new place to live. When they return to Tippy, asking for a ride back to the future, Tippy squirts water from the water bottle at Captain Underpants' face, turning him back into Mr. Krupp. While they are all falling, Crackers is getting sicker and sicker for some strange reason. Tippy then captures the five with his hand, and they all get ready to go back home. George and Harold both vow to start acting more mature and take their classes seriously as they go forward in time.
About 200,000 years later, the five notice that they're home. As they are celebrating, they notice that everything looks so old. Then Tippy tells them that he will not hurt them, but is going to destroy Captain Underpants, and that's why he brought them thirty years after the present, so that way the world doesn't have to get destroyed when Captain Underpants is destroyed. He then lets George and Harold go. Crackers is continuing to get sicker, so Sulu makes him a nest. The four friends watch as Tippy tosses Mr. Krupp around with his foot, laughing maniacally. In response, the duo make a new vow to always be themselves. After that, the Adult George and Harold disappear, leaving Old Benjamin Krupp standing there confused. Then, they snap their fingers at him, turning him into Old Captain Underpants. The duo tell old Captain Underpants to save the present Captain Underpants. He does what he is told, and when he brings Mr. Krupp back down, George and Harold snap their fingers, making TWO Captain Underpantses. They each beat up Tippy and his giant robo-boxers, but Tippy then sets off his nuclear bomb. Tippy then states to the six that the bomb will destroy the entire galaxy, as it is more powerful then a supernova. Suddenly, Crackers and Sulu sacrifice themselves by sending themselves, Tippy and the Robo-Boxers back 13.7 billion years ago. When the three go back, the bomb explodes, causing the Big Ka-Bloosh theory, incinerating Tippy and creating the universe.
13.7 billion years later, George, Harold command old Captain Underpants to gather his clothes, fly into the school, get dressed and wash his face off with water to turn back into old Mr. Krupp. They along with Present Captain Underpants realized that they are stuck in the future without a time machine. Then, Harold points out that Crackers is a girl, because she laid three eggs. The three then decide to take care of the eggs, seeing as Crackers did something for them, so in return, they'll do something for HER. As the three are walking through town possibly going to see if their homes are still around they could stay in, Melvinappears in an Gigantic, Glow-In-The-Dark, Robo-Squid and grabs Captain Underpants and the boys. They thought they was going to be in danger by Melvin again
The story begins where the last book left off with Melvin kidnapping George, Harold, and Captain Underpants. He takes them to the present where Tippy Tinkletrousers is pursuing their past selves to the past. George and Harold ask why Melvin saved them by hacking into the bank's computer and defacing their surveillance photos, because in the past Melvin hated them. Melvin simply replies that 'he had his reasons'. When they get home, Captain Underpants flies off to Mr. Krupps house "as commanded by George and Harold" to wash off with water turning back into Mean Mr. Krupp. George and Harold need a lot of sleep due to the fact they had not slept for the past thirty hours.
Two Weeks later, the Turbo Toilet 2000 attacks the city, and George and Harold make Talking Toiletcostumes and lure the Turbo Toilet 2000 to break into the Piqua Valley Home for the Reality Challenge (as George and Harold couldn't get pass the woman in the front room to see Mr. Krupp). When the two of them find an intercom after the nurse is distracted off somewhere, a quick finger snap is done through the intercom speakers by the duo in order to for Mr. Krupp to become Captain Underpants. Captain Underpants breaks out of the strap jacket taking a red curtain from the window and flies out to take a stand against the TT2000 to fight.
They begin to battle and then soon after, the Captain is victorious, but one of the Turbo Toilet 2000's tears lands on Captain Underpants' face and he turns back into Mr. Krupp who is then grabbed by the TT2000. Krupp pleads insanity to the TT2000 to be let go of but TT2000 said he will let him go if he tells him where George and Harold are. So Mr. Krupp directs the Turbo Toilet 2000 to the treehouse of George and Harold, where the Yesterday George Beard and Yesterday Harold Hutchins reside. Shortly after he finds the treehouse, the TT2000 breaks his promise of setting Mr. Krupp free and stuffs Mr. Krupp into his stomach swallowing him again like in the second book. The Turbo Toilet 2000 attempts to capture them, but he causes Crackers' eggs to crack and give birth to Tony Orlando and Dawn At first they take affection to the Yesterday boys, but then they realize that they were in danger. The three hamsterdactyls then attack the Turbo Toilet 2000 and lift him one kilometer above the ground. When the TT 2000 begs to be let go, they do exactly that and drop him, causing him to break apart into many pieces and release Mr. Krupp (who survives due to his super powers). The officers arrive and because Mr. Krupp believes he is having a weird nightmare that he keeps having, they assume that Mr. Krupp is another teacher running around in his underpants that thinks he/she is dreaming, so they arrest him.
Old George Beard and Old Harold Hutchins rush to Mr. Krupp's house needing help. As they snapped their fingers several times, Mr Krupp however wasn't coming to his trance into becoming his alter ego "Captain Underpants due to his face and head being wet at the time" Mr. Krupp wanted them to go away because to him he assumed they were acting like kids but as this was happening Kenny B. Meaner overheard what Mr. Krupp said and he grabbed the two adults and he beat them using his ape suit. Mr. Krupp demanded him not to kill them cause he didn't want any blood on his lawn. Adult George and Harold were nearly in a lot of pain but as they finally noticed that Mr. Krupp's Face was dried up and they saw that there could be their final opportunity so they quickly snapped their fingers at Mr. Krupp and he finally came into his trance becoming the amazing Captain Underpants to save his friends. Captain Underpants charged after and battled Mr. Meaner in his ape suit and Mr. Meaner was defeated for now and taken to jail.
The next day after eating an egg salad sandwich with pickle relish, Mr. Meaner aka Sir Stinks-A-Lot turns into a blob (because the egg salad contains mayonnaise and he added pickle relish; this would create Zygo-Gogozizzle 24). He then causes havoc downtown wanting revenge on Captain Underpants for being locked up. Captain Underpants returns to fight him back, but when Old George and Old Harold are captured, Captain Underpants couldn’t save them, as Sir Stinks-A-Lot turns him back into Mr. Krupp with a lot of water, therefore falling down (he was still unharmed because of his superpowers).
Sir Stinks-A-Lot then extracts the superpowers as well as the effects from the 3D Hypno Ring ceasing the existence of Captain Underpants from Mr. Krupp. Mr. Krupp (dressed as the fallen hero Captain Underpants) then runs off screaming in terror Later Things were back to the way they were, and as young George and Harold return their older counterparts to their own time, they find that Mr. Krupp didn’t turn into Captain Underpants at the snap of a finger, because Mr. Meaner erased Captain Underpants from existence. As a woman was passing by jogging listening to music and snapping her fingers, Mr. Krupp was still as mean as usual yelling at the woman passing by. George and Harold and their older counterparts decided that they were not going to contribute to the plot and fix the problem which indicated that they were going to move on without Captain Underpants
In the beginning of the book, he is kidnapped by Deputy Dangerous and Danger Dog. Using the Super Power Taker-Awayer Ray 2000, they remove Captain Underpants' superpowers. Near the end, Super Diaper Baby and Diaper Dog save him and give him a carton of Super Power Juice, restoring his powers.
Mentioned in the prologue.
Captain Underpants is portrayed much the same way as his book self, though he is less intelligent than his book counterpart as he believes that a mime is trapped in a box and he places an old lady in a tree along with her cat instead of helping the cat out of the tree as she wanted. Unlike the books, Captain Underpants acquires his powers after getting bathed in the Nuclear Toilet Water from Professor Poopypants' Great Mech Suit instead of drinking Extra Strength Super Power Juice.
- He, Mr. Krupp, George, and Harold are the only characters to appear in every episode of The Epic Tales of Captain Underpants.
- In Book 3, it is revealed that he knows of his missions and heroics in the Treehouse Comix books George and Harold wrote of him. This is likely because, as discovered in Book 1, Mr. Krupp has taken away every issue of their Captain Underpants comics and has them in storage. (implying at some point he has read them all).
- In the film, he reminisces about his missions and heroics as well as reads the comics about himself.
- In the film, he remembers the plunger he used to fight the toilets in book 2.
- Although he is unaware of Mr. Krupp, he does know where his office and house is.
- In George and Harold's comic books, he lacks a secret identity. Instead, he watches over the city, ready to save the day whenever there's trouble.
- In the Treehouse Comix's version, it is revealed in Book 5 that he is from a planet called Underpanty World. Since the Planet was ending due to the Wedgie Warlords using the giant can of spray starch, his parents named Daddy Long Johns and Princess Pantyhose sent him to earth before the people on the planet perished by the spray starch.
- In the comic, he swallowed some kind of amulet that was going to be used to protect his home planet from spray starch.
- In the comic books by Treehouse Comix Inc, his underwear is not just regular underwear, but a special kind he uses, because he can click a button and a roll of toilet paper will come out and he will use is to swing on, or tie his villains up. Or a tiny toilet to squirt villains in the face.
- The metaphor he uses to help restore his powers is "I SUMMON THE POWER OF UNDERPANTY WORLD!"
- George and Harold only learn how to transform Captain Underpants in the end of the book when they splash him in the face with water, unaware at the time that snapping their fingers will turn Mr. Krupp back into Captain Underpants and that it wasn't a permanent solution to returning Mr. Krupp to normal. But in the movie, George and Harold catch on more quickly and even have fun transforming Mr. Krupp into Captain Underpants and vise versa.
- It's unknown how Mr Krupp is able to turn back into Captain Underpants right after he was splashed with water then hears the snap of a finger again, but in the book, if Mr. Krupp's face and/or head is still too wet he cannot change into Captain Underpants unless he's all dry. In the show, even if he is wet not on his head or face he cannot.
- In the book series continuity, Captain Underpants no longer exists in Mr. Krupp's body, as Sir Stinks-a-Lot wiped his superpowers and the 3D Hypno-Ring's effect from his brain. This creates a plot hole because when Tippy Tinkletrousers tries to kill Captain Underpants 30 years in the future George and Harold are able to snap their fingers to turn Future Mr. Krupp into Captain Underpants.
- Dav Pilkey stated that Captain Underpants may return again in a Dog Man book. However, it is unknown if Mr. Krupp will be hypnotised into being him again. It might be possible that he will only be in the Dog Man stories and team up with the titular hero.
- He is based on Superman from DC Comics.
- Captain Underpants' concept is a play on how most superheroes look like they are flying around in their underwear.
- In the movie and show, George and Harold drew Captain Underpants by basing his appearance more like Mr. Krupp's likeness in the comics. But in the books, Captain Underpants is based on another appearance nothing like Mr. Krupp's likeness.
- Captain Underpants sometimes uses anything as his red cape. In Captain Underpants: The First Epic Movie, he uses the school window curtain and restaurant tablecloth as his red cape with tiny black dots on it. In The Epic Tales of Captain Underpants, he sometimes uses someone's sweater as a cape, his original cape that's fully red, or his red cape with light red spots on it. In The Epic Tales of Captain Underpants in Space!, he also uses his space suit as a cape.
- In the TV series, Captain Underpants often says "Oooooooo" whenever he finds something surprising or interesting.
- Captain Underpants and Mr. Krupp have two different types of accents in the series. Mr. Krupp's voice is high pitched and hoarse, while Captain Underpants' voice is deeper and bolder.
- Captain Underpants' enemies tend to compare him to a giant baby with a cape.
- In many occasions, the book version of Captain Underpants is shown to be smarter than his animated counterparts.
- As shown in Captain Underpants: The First Epic Movie, he adores carnivals to the point of abandoning any semblance of common sense to make it more extravagant.
- Although he's a deuteragonist, the whole franchise is named after him.
- There is a 1989 prototype of Captain Underpants.
- It is possible he was not erased from Mr. Krupp's mind in the book series, because in Captain Underpants and the Revolting Revenge of the Radioactive Robo-Boxers, Old Benjamin Krupp was able to turn into Captain Underpants, even after the events of Captain Underpants and the Sensational Saga of Sir Stinks-A-Lot.
Now it is time to fly again! - Captain Underpants' movie quote.
Stand down Poopypants! - in the movie.
Depending on the media, Captain Underpants either gets his superpowers from drinking a carton of Extra-Strength Super Power Juice (book series and TV series) or from consuming the liquidized leftover food inside the Turbo Toilet 2000 (movie).
- Superhuman Strength
- The power to overcome Spray Starch
- Wedgie Power
- 100% Cotton-Powered Vision
- Laser Vision Eyes
- Superhuman Durability.
- Unlimited Underpants (film and TV series)
- Able to survive in space without a suit (TV series in In Space)
- Water to face (in 'real life')
- Spray Starch (comic book only)
- Bee Stings (Netflix Series)