Overview List indicators: • A dark gray cell indicates that the character was not in the property or that the character's presence in the property has yet to be announced. • A
Main indicates a character had a starring role in the property. • A
Supporting indicates the character appeared in two or more times within the property. • A
Guest indicates the character appeared once in the property.
Main characters •
George Beard and
Harold Hutchins – George Beard and Harold Hutchins are two fourth-grade pranksters, best friends, and next-door neighbors who serve as the main protagonists of the series. They started a comic book company called "Treehouse Comix, Inc.", and co-create the Captain Underpants comics at the center of the novels. They attend Jerome Horwitz Elementary School in Piqua, Ohio, a school named for Curly of the Three Stooges. In
Captain Underpants: The First Epic Movie, they are respectively voiced by
Kevin Hart and
Thomas Middleditch and by Ramone Hamilton and Jay Gragnani in the animated series,
The Epic Tales of Captain Underpants respectively. •
Mr. Benjamin "Benny" Krupp / Captain Underpants – Mr. Benjamin Krupp is the principal of Jerome Horwitz Elementary School and is the antagonist to George and Harold in the earlier books. Whenever he hears the sound of fingers snapping, he transforms into Captain Underpants, a superhero wearing white briefs and a red cape with black polka dots, reverting to his original self when water is poured on his head. From the third book,
Captain Underpants and the Invasion of the Incredibly Naughty Cafeteria Ladies from Outer Space, onward, Captain Underpants acquires superhuman strength, durability, and flight after consuming "Extra-Strength Super Power Juice”, belonging to the evil aliens Zorx, Klax, and Jennifer. In the movie, he is voiced by
Ed Helms, and in the animated series, by
Nat Faxon. •
Melvin Richard Sneedly – Melvin Sneedly is a classmate of George and Harold who is characterized as a highly intelligent student and a frequent inventor. He functions as a recurring rival to George and Harold across the series and, in the eleventh book,
Captain Underpants and the Tyrannical Retaliation of the Turbo Toilet 2000, briefly becomes a superhero known as Big Melvin. In the film, he is voiced by
Jordan Peele and in the series by
Jorge Diaz. •
Sulu and
Crackers – Sulu is a bionic hamster adopted by George and Harold, and Crackers is a
Quetzalcoatlus, that the boys bring back from a time-travel adventure; the pair later have children together in the series named Tony, Orlando, and Dawn.
Recurring In book 11, when the teachers saw two Georges and two Harolds, they think they are dreaming and then they go naked. They are arrested when Miss Fitt pulled down Officer McWiggly's pants. Mr Hand in
the series gets hired. •
Mr. Kenny Brian Meaner – Mr. Meaner is Jerome Horwitz Elementary School's gym teacher. He is depicted as being an overweight man and with a personality similar to Mr. Krupp's. Like him, he is cruel to students and often yells at them. He appeared in the Netflix series, where he is depicted as being ignorant and talks in a stutter by saying "yeah yeah yeah yeah." In book 12, Meaner becomes Sir Stinks-A-Lot. His name is a pun on the word "misdemeanor" or the saying "can he be meaner". He is voiced by
David Koechner in the TV series. In the TV series, he has an alternate ego by the name of
Sargeant Boxers, which was made as a replacement for Captain Underpants in the first episode of the second season. •
Miss Edith Anthrope – The school secretary who is often shown to be in a bad mood. Like all the other teachers at the school including Mr. Krupp, she is unkind to children. She is slightly overweight, in contrast to most of the other teachers. In the movie, she is on hold for three days thinking she will win a contest with a cash prize of $1 billion. In
the movie she does not speak, but in
the series, she is voiced by Patty Mattson where she is glum but yells "Fine!". A running gag in the series involves her entering Mr. Krupp's office saying "Did you call me?" followed by something else she says. Her name is a pun of the word "
misanthrope" or by saying "eat it/miss and throw up." •
Mr. Morty Fyde – Mr. Fyde was the science teacher at Jerome Horwitz Elementary School. Unlike all the other grown-ups in the school, he is rather dorky and stupid. The events of the first three books gradually cause him to believe himself is insane and resign from his job to put himself in a mental institution (but in the movie Mr. Krupp simply fires Fyde because he'd rather spend time with his family instead of judge the school science fair and Krupp considers this unacceptable). His name is a pun on the words "mystified" and "mortified." In the film, he is voiced by
Mel Rodriguez and in the series he is voiced by
Stephen Root, where he is released from the mental institution, though he becomes nervous around loud noise, which is unfortunate for Mr. Fyde; an elementary school is practically built on noise. One of Melvin's inventions accidentally fuses Mr. Fyde with an
avocado pit belonging to George and Harold, turning him into a giant avocado monster named Avocadwoe that attacks everything that makes loud sounds. Mr. Fyde is planted by Captain Underpants and he is turned into an avocado tree in a peaceful forest behind the school, something that Mr. Fyde is content with. •
Ms. Tara Ribble – Ms. Ribble is the homeroom teacher of George and Harold's 4th-grade class. In book 5, she is hypnotized into becoming Wedgie Woman. Her name is a pun on the words "terrible" and "miserable." Voiced by
Dee Dee Rescher in the movie and
Laraine Newman in the TV series. •
Miss Singerbrains – Miss Singerbrains is the librarian at Jerome Horwitz Elementary School who banned all but one of the books in the library and eventually closed down the library. Her name is a pun on the saying "missing her brains". •
Mr. Riles Rected – Mr. Rected is the guidance counselor at Jerome Horwitz Elementary School. He is very nasty to students, especially George and Harold, and he is often seen hanging with Mr. Krupp, Mr. Meaner, Miss Anthrope, and Ms. Ribble. His name is a pun on the word "misdirected." He is voiced by
Brian Posehn in the film and
Jorge Diaz in the animated series. •
Ms. Dayken – Ms. Dayken is a member of the teaching board at Jerome Horwitz Elementary school. Her name is a pun on the word "mistaken". In the film, she is voiced by Susan Fitzer and was George and Harold's kindergarten teacher where she teaches about the planets, including "
Uranus," which the boys found amusing. •
Mr. Rustworthy – Mr. Rustworthy is (according to his tie) the music teacher of Jerome Horwitz Elementary School. His name is a pun on the word "mistrustworthy". In the series, he is replaced by a different music teacher,
Ms. Herd (a pun on "misheard"). •
The Lunch Ladies – The Lunch Ladies are the three women who run the cafeteria. They are notorious for cooking horrible, inedible, and possibly lethal food. They quit in the third book when Mr. Krupp says he cannot punish George and Harold for their antics without proof, though they are possibly rehired after the replacements are revealed to be aliens. Two of the Lunch Ladies are
Miss Creant, the head lunch lady, and
Mrs. DePoint, the cook. The revealed names are puns on the word "Miscreant" and the phrase "Misses the point". •
Doctor Diaper (known alternatively as
Doctor Nappy in the UK) – A diaper-clad mad scientist and the first villain Captain Underpants ever faced. •
The Talking Toilets – An army of living toilets created by George and Harold, who were accidentally brought into the real world with a modified photocopier. All they could say is the phrase "Yum, yum, eat 'em up!" •
The Turbo Toilet 2000 – A giant toilet created by George and Harold, who was accidentally brought into the real world with a modified photocopier. After he was defeated by the Incredible Robo-Plunger, he and the other toilets were taken to
Uranus where he remained for several books until being brought back to life by juice from the destroyed Robo-Plunger. In the film, it was now Melvin's invention that was grown by Poopypants with his size ray. •
The Incredible Robo-Plunger – A giant robot created by George and Harold to defeat the Turbo Toilet 2000. Afterwards, he repaired the school and took all the toilets to Uranus where he remained for several books until he was hit on the head by a kickball kicked into space by the Harold 2000. He is then rebuilt by the revived Turbo Toilet 2000 into a rocket scooter so the toilet could return to earth. •
Zorx,
Klax, and
Jennifer – Three space aliens who planned to invade Piqua, Ohio. They are the main antagonists of the
third book. They disguised themselves as lunch ladies to turn the students of Jerome Horwitz Elementary School into Zombie Nerds by using Evil Zombie Nerd Juice. •
The Dandelion of Doom – A
dandelion that absorbed alien super evil rapid-growth juice, causing it to grow into a giant monster. •
Tippy Tinkletrousers (formerly known as
Professor Pippy Pee-Pee Poopypants, and in the film as
Prof. Pee-Pee Diarrheastien Poopypants Esq.) – A scientist who comes from a foreign country where everyone has a silly name. In book 4, he forces everyone on earth to change their names into a silly one. After his defeat, Professor Poopypants changes his name, suggested by George rather than forcing everybody to change theirs. But Poopypants does not change his name to something normal, instead, he changes it to his grandfather's name Tippy Tinkletrousers. In the film, he is voiced by
Nick Kroll. •
Wedgie Woman (
Ms. Ribble) – A villain created by George and Harold who was based on their teacher Ms. Ribble. After a second mishap with the Hypno-Ring, it convinced her that she is Wedgie Woman. At first, she has no superpowers, but after her hairstyle gets splattered with superpower juice from the third book her hair transforms into arms and she gains super-intelligence. •
Robo-George and The Harold 2000 – Two giant robots built by Wedgie Woman based on George and Harold. They were fully obedient to Wedgie Woman; each had a vast arsenal of powerful weapons and gadgets and were programmed to destroy Captain Underpants once they heard him say "Tra-la-laaa!" •
The Bionic Booger Boy (
Melvin Sneedly) – A fusion of Melvin Sneedly, boogers, and a super-powered robot. His growth is triggered by a field trip to a tissue factory. •
Carl,
Trixie and
Frankenbooger (
The Three Robo-Boogers) – Boogers who all come from the Bionic Booger Boy. They all share a weakness to oranges, which Captain Underpants successfully used to destroy the rampaging trio of living mucus. Carl had the Bionic Booger Boy's legs, Trixie had the tentacles, and Frankenbooger had the arms. Whenever they ate, they became bigger and more evil. •
Evil George and
Evil Harold – Alternative versions and negative counterparts of George and Harold from an alternate dimension who are both intelligent and evil. They are the main
antagonists, along with Captain Blunderpants, of the
8th book in the series. They helped Captain Blunderpants and unlike the sketchy, amateurish George and Harold they are good authors and illustrators (ironically, the main George and Harold consider the alternative George and Harold's work inferior). Additionally, they also tended to change the signs into evil phrases (while their counterparts often change the signs into funny words). •
Captain Blunderpants – The opposite and evil counterpart of Captain Underpants from an alternate dimension, who has a toupee and looks and acts more like Krupp, while the alternate Krupp is nice. His transformation process is the opposite; when water is splashed on him, he becomes the evil Captain Blunderpants and when someone snaps their fingers, he becomes the nice Mr. Krupp. •
Kipper Krupp – A sixth-grade bully and Benjamin's nephew and Jasper Krupp's son, who would bully George, Harold, and other children when they were all in kindergarten. Due to a series of pranks that George and Harold conducted, he would eventually become nicer to the children along with his also mischievous friends
Finkstein,
Bugg, and
Loogie. •
Sir Stinks-A-Lot (
Mr. Meaner) – Mr. Meaner later becomes the alter ego of Sir Stinks-A-Lot, an evil hypnotist. While in prison, Meaner transforms into a blob of pure energy after eating an egg salad sandwich. He later removes Captain Underpants's superpowers and the effects of the Hypno ring. ==Reception==