Codename: Kids Next Door

The show revolves around a group of five 10-year old kids, using codenames Numbers 1 through 5, who are the main home operatives of what is known as Sector V, which is part of a worldwide espionage-style organization called the Kids Next Door. Their mission is to fight crimes against kids (such as homework and flossing), many of which are willingly committed by "evil" adults, senior citizens, teenagers, and other children. Numbuh 1 is the bald, astute, no-nonsense, workaholic British-American boy Nigel Uno, leader of Sector V. Numbuh 2 is the overweight, intellectual, aviation enthusiastic, pun-cracking Irish-American boy Hoagie Gilligan Jr. Numbuh 3 is the happy-go-lucky Japanese-American girl Kuki Sanban. Numbuh 4 is the short-tempered, irrational, and fighting-prone Australian-American boy Wallabee Beatles. Numbuh 5 is the intelligent, laid-back, tomboyish African-American girl Abigail Lincoln.

Following a period of training, every member of the Kids Next Door chooses a number or alphanumeric code (deliberately pronounced and spelled as "Numbuh") and is sent to a "sector" that acts as their home base. The sector headquarters, like some of the organization's bases and facilities, are tree houses, with both treehouse and the tree it is in being of ludicrous proportions, and often suited to their environment. This includes a base constructed beneath the Arctic ice shelf, and a base built into a large pine tree. The main headquarters of the Kids Next Door is a treehouse Moon Base. The Kids Next Door follow their oath of protecting other kids as well as battling adulthood until the age of 13 when they are "decommissioned", a process of wiping their memories of any past KND activity and warping their minds. Such a practice has inevitably led to the creation of many KND villains who escaped decommissioning (such as Numbuh 5's older sister Cree, formerly known as Numbuh 11, and Chad, formerly known as Numbuh 274 and supreme commander of the Kids Next Door).

The practice of strict decommissioning at age 13 was later on revealed to be subject to exceptions: kids who are deemed exceptional agents are offered the chance to carry on in KND as spies infiltrating the teen organization in the Teens Next Door.[7] Decommissioning has also proved reversible due to a "re-commissioning" module used four times in the series (once in Operation: E.N.D. and three times in Operation: Z.E.R.O.).[8][9]

KND agents utilize a vast array of mechanical, electronic gadgets, weapons, and machinery, collectively referred to as 2x4 (two-by-four) technology. The KND's 2x4 technology was originally conceived as being constructed from an assortment of objects, mostly including those that are found in common households; a theme their technology continued to adhere to. However, as the series progressed, the kind of objects their technology was constructed from became bigger, consisting of things such as large vehicles and small buildings. Not only that, but the complexity of their technology, such as their defensive weaponry and means of transportation, advanced to such absurd levels as to be considered science fiction, despite all of it still being constructed from nothing but an assortment of objects.

The episodes are titularly presented as the missions of the members of Sector V in the Kids Next Door, denoted as "Operation:" followed by an acronym that can give viewers clues as to what each mission is about. Most episodes are divided into two parts, each a different mission, while some episodes consist of two directly linked parts with one mission. Usually, the episodes have very little continuity with each other, although occasionally an episode will have a reference to at least one earlier episode and/or lead to consequences in later ones. Season Five's "Operation: O.U.T.B.R.E.A.K." is a direct continuation of the episode "Operation: V.I.R.U.S.", and Season Six's "Operation: S.C.I.E.N.C.E." leads into "Operation: A.M.I.S.H." while another pair of Season Six episodes; "Operation: R.E.C.E.S.S." and "Operation: H.A.M.S.T.E.R.", occur simultaneously, the latter showing what sort of thing transpires while the team is away.

Stories in the earlier episodes were often about typical childhood problems but magnified and exaggerated. As the series progressed, a more complex and continuous storyline developed. The final season revolved around the mysterious Splinter Cell within the KND itself observing Numbuh One for an unknown assignment, which was concluded in the series finale "Operation: I.N.T.E.R.V.I.E.W.S.".

The show frequently contains references to many films and other television series, especially in the later seasons, such as Star Wars, Ghostbusters, Planet of the Apes, Jaws, Jurassic Park, The Lord of the Rings, Godzilla, The Terminator, Spider-Man, Dragon Ball Z, James Bond, Star Trek, Transformers, Harry Potter, Rambo, Alien, The Matrix, X-Men, Predator, RoboCop, Men in Black, Doctor Who, Indiana Jones, and Mission Impossible; with James Bond, Star Trek, and Star Wars being the most prominently referenced in the series.

• Numbuh 1/Nigel Uno (voiced by Benjamin Diskin) - the leader and head operative of Sector V.
• Numbuh 2/Hogarth Pennywhistle "Hoagie" Gilligan, Jr. (voiced by Diskin) - the joke-cracking engineer of Sector V.
• Numbuh 3/Kuki Sanban (voiced by Lauren Tom) - the happy-go-lucky tactician and medic of Sector V.
• Numbuh 4/Wallabee "Wally" Beetles (voiced by Dee Bradley Baker) - the brash combatant of Sector V.
• Numbuh 5/Abigail "Abby" Lincoln (voiced by Cree Summer) - the intelligent, relaxed second-in-command/spy of Sector V.

• Numbuh 6/Bradley (vocalized by Baker), a skunk that became an honorary member of Sector V after Numbuh 2 and Numbuh 3 saved him in the streets. In "Operation: H.O.S.P.I.T.A.L." Bradley becomes a cyborg after Numbuh 2 once again saves his life in the hospital after getting hit by a car.
• Numbuh 9/Maurice (voiced by Khary Payton), a former member of Sector V who was reinstated to the Teens Next Door, a special operations group that fake being decommissioned in their 13th birthday so they can learn information from both adults and teenagers.
• Numbuh 60/Patton Drilovsky (voiced by Matt Levin), a high ranking operative of the Kids Next Door Arctic Base.
• Numbuh 83/Sonia (voiced by Janice Kawaye), The Soda, Snacks, and Treats officer of Sector W, she has a irrational fear of the dark and will go into a blind rage when she is forced towards it.
• Numbuh 84/Lee (voiced by Kawaye), The tactical Yo-yo Specialist of Sector W.
• Numbuh 86/Fanny Fulbright (voiced by Jennifer Hale), the Head of Decommissioning and Global Tactical Officer of the KND Organization.
• Numbuh 92 and Numbuh 93 (voiced by Diskin and Strong), two KND operatives who reside on the Kids Next Door Moonbase.
• Numbuh 362/Rachel McKenzie (voiced by Rachael MacFarlane), the Supreme Leader of the KND Organization.
• Numbuh 74.239 and Numbuh Infinity (Dave Wittenberg as 74.239 and Phil LaMarr as Infinity), two KND operatives who both worked for the Splinter Cell, a shadowy faction of the Kids Next Door. They have manipulated events to sign Numbuh 1 to the Galactic KND.

• Father/Benedict Uno (voiced by Maurice LaMarche when wearing the silhouette suit as Father and Jeff Bennett when without it as Benedict), the arch-nemesis of the KND, the main villain of the series, and the 'adoptive' father of the Delightful Children From Down The Lane. He is also Nigel's paternal uncle, Monty's brother. In "Operation: Z.E.R.O.", the aforementioned family relation is revealed, as well as that Father kidnapped the kids formerly known as Sector Z and permanently brainwashed them to become the Delightful Children.
• The Delightful Children From Down The Lane (voiced by Diskin, Baker & Summer),[lower-alpha 1] five 'delightfulized' kids, and Father's children/henchmen. In "Operation: Z.E.R.O.", they are revealed to be the former members of the missing Sector Z; Bruce, Ashley, David, Lenny, and Constance (clockwise from the front). 'Delightfulization' is shown to be a form of brainwashing throughout the series, and the process on Sector Z was boosted 'eleventy-billionfold' by a blown fuse, turning them into not only delightfulized children, but a hivemind as well. Unlike with other 'delightfulized' children, the Delightful Children's process was made permanent by this boost of power, meaning any attempt to bring back Sector Z can only be temporary. On top of that, Father is revealed as Nigel's paternal uncle, making the Delightful Children Nigel's 'adopted' cousins.
• Cree Lincoln (voiced by Summer), Numbuh 5's older sister, leader of the Teen Ninjas, and an apprentice to Father. She was originally a KND operative Numbuh 11.
• Chad Dickson (voiced by Jason Harris), Formerly Numbuh 274, Chad was the supreme leader of the Kids Next Door until it was revealed in "Operation: E.N.D." that he hidden his thirteenth birthday to the KND and arranged Sector V's decommission. Due to his treason he allies with the adults and joined the Teen Ninjas. In "Operation: T.R.E.A.T.Y." he was actually a TND operative working for the Splinter Cell.
• Mr. Boss (voiced by Bennett), a corporate executive, and the de facto second-in-command of the KND's standard rogues gallery. In "Operation: D.A.D.D.Y.", it is revealed that he is Numbuh 86's father.
• The Toiletnator/Lou Pottingsworth III (voiced by Baker), a toilet-themed incompetent villain, being considered the lamest villain by the KND and by other villains to the point where they consider fellow toilet-themed villain Pottymouth superior to him, despite being the worst threat, he is shown to have toilet based powers as seen within "Operation: C.A.N.Y.O.N.". In a comic spin-off it is revealed that he is Numbuh 4's long lost uncle.
• Stickybeard (voiced by Mark Hamill), a candy-loving pirate and a rival of Numbuh 5's due to their mutual obsession with sugar. Despite being sour towards the Kids Next Door, he does show a "sweet tooth" such as saving Sector V from the Great White Asparagus (which he loathes more then kids) and helping Numbuh 5 save Heinrich from cursed licorice pirates.
• Knightbrace/Mr. Jelly (voiced by Tom Kenny), an oral health-themed villain who performs painful and unnecessary dental and orthodontic procedures. In his debut episode, "Operation T.E.E.T.H.", his true identity is Mr. Jelly, the former owner of a candy shop the KND frequently visit. Mr. Jelly always wanted to be a dentist ever since he was a child, but was expelled from dental school for attempting to put braces on babies. He was forced to work in his family's candy store but went insane and became Knightbrace after seeing kid after kid munch on the sweets damaging their teeth. Despite his hatred for sugar products, he does like taffy.
• The Common Cold (voiced by Kenny), a sickness based villain who uses his own snout to render all KND operatives sick so they'll be too weak on stopping other adults plans.
• Gramma Stuffum (voiced by DeLisle), an old lady obsessed with force-feeding her disgusting food to children to make them unable to move so that they can't bother adults.
• Count Spankulot (voiced by Daran Norris), a vampire who spanks naughty children. Like the Toiletnator, he wants to join a group but his spank addiction always gets him rejected. In "Operation: L.O.C.K.D.O.W.N." he can actually turn people into spank-happy vampires just by taking out his gloves and can only be cured by spanking him back.
• Mr. John Wink and Mr. Timothy Fibb (voiced by Kenny & Baker), a pair of villains who use robotic chairs to fight. They were transformed into a buffalo and walrus by unknown ways. In "Operation C.O.W.G.I.R.L.", both of them used to be members of Cowboys Kids Club, but Timothy and John became villains due to fellow Cowboy Kids Club member, Lasso Lass, going to the prom with Texas Tommy instead of Timothy.
• Crazy Old Cat Lady (voiced by Grey DeLisle), an old woman who lives with thousands of black and white cats.
• Professor XXXL (voiced by Welker), a villain who wants to create the perfect snow cone that has ever been made, every time he appears he gets different animalistic limbs in his body.
• Chester (voiced by Kenny), a greedy businessman who wants to make money by the expense of children. Some of his numerous schemes include brainwashing campers for labor, selling children as burgers to sharks and putting Numbuh 1 in a dream with the help of his Happy Headband.
• Mega Mom and Destructo Dad (voiced by Bennett and DeLisle), Numbuh 274's parents that wanted their son to be the best by petrifying the other KND operatives. They were easily defeated when 274 threatens them by quitting every extra curricular activity he's assigned.
• Mr. Fizz (voiced by Bennett), a businessman who is the head of the Soda Control Board who "ilegalize" what children should not drink such as raising the root beer drinking age to thirteen.
• The Great Puttinski / Rupert Puttkin (voiced by Rob Paulsen), miniature golf champion who takes the sport very seriously. After losing to Numbuh 2, he shrinks him down to size in his basement where he created his own course (all the while to not disturb his mother).
• Senior Citizen Squad (voiced by Milo, Kenny & Baker), a group of senior citizens led by Numbuh 2's grandmother, Lydia Gilligan, who along with her companions, Sheldon and Maurice, use an anti-aging cream that temporarily turns them into teenagers.
• Ice Cream Men (voiced by Kenny, Baker, Kevin Michael Richardson & Norris), men who operate Ice Cream Trucks, and serve mainly as henchmen to the Delightful Children and Father.
• Henrietta "Heinrich" Von Marzipan (voiced by Baker while cursed & Candi Milo while uncursed), Numbuh 5's arch-rival, who travels the world in search of rare candy and will often go to villainous extremes to get it. She hates Numbuh 5 for an unknown past event in Guatemala, eventually explained in "Operation: C.A.R.A.M.E.L.". In the series, she appears to be a boy, but in "Operation: C.A.R.A.M.E.L.", it is revealed that she is actually female, suffering under the effects of a curse, and she and Numbuh 5 reconcile with each other after she is helped to become her true self again.
• James Nixon McGarfield (voiced by Kenny), McGarfield was the Fourth Grade President-for-life of Gallagher Elementary until it was revealed that he allied with Father and began abusing his power until "Operation: S.N.O.W.I.N.G.".
• The Big Badolescent/Laura Limpin (voiced by DeLisle and Baker when turned), a little girl who has a "condition" that turns her into a hulking monster when she gets angry, she'll eventually calms down when she gets in her way.
• The Six-Gum Gang (all voiced by Hale, Kenny, Diskin and Baker), a gang of child robbers who worked for the Delightful Children to steal other children's homework and pass it off as their own.
• The Interesting Twins From Beneath The Mountain (voiced by Kenny, Strong and Hale), two Japanese twins who worked for the Delightful Children, there faces are painted similar to the Yin and Yang symbol. In "Operation: T.R.I.P.", they were following Numbuh 3 on her trip to Japan so they can infiltrate the home base of the Japanese Kids Next Door.
• King Sandy (voiced by James Arnold Taylor), a average little kid that always portrays himself as a tyrannical king and hates being told that he's pretending, he is escorted with the Knights of the Round Towel (who are actually his cousins). He once tried to make Numbuh 3 his queen but not before he sets his eyes on her little sister, Mushi.
• Grandfather (voiced by Neil Ross), Monty and Benedict's father who is the main antagonist in "Operation: Z.E.R.O.". His main goal was to turn all children and adults into obedient elderly zombies to reclaim dominion across the world, he was successfully defeated by the recommissioned Numbuh 0 by placing both Grandfather and himself in the Decommissioning Chamber which erased their memories.

• Lizzie Devine (voiced by DeLisle), Numbuh 1's girlfriend and then later ex-girlfriend; they broke up at the end of the season 6 episode, "Operation: G.I.R.L.F.R.I.E.N.D.".
• Numbuh 0/Montgomery "Monty" Uno (voiced by Frank Welker in adult mode and Dave Wittenberg in Numbuh 0 mode), Numbuh 1's father.
• Mrs. Uno (voiced by Hale), Numbuh 1's mother and Father's sister-in-law. In "Operation: I.N.T.E.R.V.I.E.W.S.", she was originally a KND operative Numbuh 999.
• Betty Gilligan (voiced by Milo), Numbuh 2's mother.
• Thomas "Tommy" Gilligan (voiced by Baker), Numbuh 2's little brother. In "Operation: G.R.A.D.U.A.T.E.S.", he temporary becomes a KND operative "Numbuh T" until he resigns himself and became a vigilante going by "The Tommy".
• Kani Sanban (voiced by Keone Young), Numbuh 3's father.
• Genki Sanban (voiced by Tom), Numbuh 3's mother.
• Mushi Sanban (voiced by Tara Strong and Jennifer Hale), Numbuh 3's little sister. In season 4 she later becomes a villain after "murdering" her sister's new Rainbow Monkey out of jealousy, later she kidnaps Count Spankulot to create Spankenstine as revenge towards Numbuh 2.
• Sydney Beetles (voiced by Bennett), Numbuh 4's father.
• Mrs. Beetles (voiced by Hale), Numbuh 4's mother.
• Joey Beetles (voiced by Baker), Numbuh 4's baby brother.
• Dr. Lincoln (voiced by Richardson), Numbuh 5's Father who is inspired by Cliff Huxtable from The Cosby Show.
• Mrs. Lincoln (voiced by Summer), Numbuh 5's mother.

In 2005, the series won the Best Television Series for Children Award at the Ottawa International Animation Festival for "Operation: A.R.C.H.I.V.E.", which was written by Mr. Warburton and Mo Willems and storyboarded by Guy Moore and Quack Leard.[14]

The following year, "Operation: L.I.C.O.R.I.C.E." won the Festival's Collideascope Award for Television Animation for Children.[15]

• Cartoon Network (2002–2008; 2009–2014)
• Kids' WB (2004)
• Boomerang (February 2017–March 2017; January 2, 2018 – May 27, 2019, June 8, 2021 – present)[16]

Two DVDs in two volumes were released of the series, totaling sixteen episodes by Warner Home Video. The entire series is available on digital purchase in six seasons. On May 30, 2019, the entire series, except for the "Operation: Z.E.R.O." TV movie, was added to the Boomerang streaming service and its VRV channel.

On an episode of The Grim Adventures of Billy & Mandy entitled "Sickly Sweet", a scene depicts Grim watching Codename: Kids Next Door. Also, in Billy & Mandy's Big Boogey Adventure, Numbuh Three makes a cameo as Grim's replacement. Numbuh Two also made a cameo in "Billy & Mandy Moon the Moon". Also, in the MAD episode "Taking Nemo / Once Upon a Toon", Numbuh One makes a cameo as one of the cartoon characters who has forgotten his identity. The show was also referenced in the New Boyz song "Tough Kids".[20] In the 2004 film Sideways, the show is playing on Miles' mother's television set. The Delightful Children from Down the Lane were reviewed on the Orientation Videos for Villains of Villainous "The Lost Cases of the Treehouse". Numbuh Five made a cameo in the OK K.O.! Let's Be Heroes episode "Crossover Nexus". In the Craig of the Creek episode "Kelsey the Elder", Barry mentions this show.

Stories featuring the Kids Next Door have been featured in the comic series Cartoon Cartoons, Cartoon Network Block Party, and Cartoon Network Action Pack from DC Comics. The characters are also featured in the books 2x4 Technology Handbook and Sooper Secrets and Boomerang Bloopers, both by Alison Wilgus. The characters appeared in a one-shot tie-in for Cartoon Network and IDW's Super Secret Crisis War crossover comic in 2014.

A trading card game based on the series was launched by Wizards of the Coast in July 2005.

Two video games were released for the series: Operation: S.O.D.A. in 2004 for the Game Boy Advance and Operation: V.I.D.E.O.G.A.M.E. in 2005 for PlayStation 2, Xbox, and GameCube. Several browser games were also released on the Cartoon Network website. The MMORPG style game Operation: B.E.S.T. was playable for a brief time in 2005, but was shut down shortly thereafter.

In Cartoon Network Universe: FusionFall, Numbuhs One through Five, and villains Father, Toiletnator, and Stickybeard appear as non-playable characters. KNDefense armor and 2x4 Tech weapons are available for players, Sector V's treehouse can be explored, and KND S.C.A.M.P.E.R.s can be used for transport. In Cartoon Network: Punch Time Explosion, Father and Numbuh 1 are playable, Sector V Treehouse and the C.O.O.L.-B.U.S. are arenas, and Numbuh 2 and Stickybeard are assisted characters. In the console versions, Toiletnator is a playable character, Numbuh 4 is an assist character, and KND Moonbase is an arena.