Section about other KND characters.
Numbuh 1's Family
Numbuh 1's father, obsessed with Sousaphone music and spending quality time with his son. Numbuh 1 is incredibly embarrassed by him, but loves him deep down. Voiced by Frank Welker and Dave Wittenberg as a kid.
- Action Dad: When recommissioned in Operation: Z.E.R.O., he becomes a formidable ally to his son.
- Affectionate Nickname: "Nigel ol' bean," for his son.
- Amazingly Embarrassing Parents: His son views him as an embarrassing dad some of the time.
- Archnemesis Dad: His father, Grandfather, ruled the world as an Evil Overlord who he rose up against to save the world. He's recommissioned to deal with him when he's restored to power.
- Badass Mustache: Have you seen it?
- Bald of Awesome: He was a former Kids Next Door operative and the only hair he's got is his side hair sticking out.
- Back for the Finale: Recommissioned as Numbuh Zero for the second time in "Operation: I.N.T.E.R.V.I.E.W.S.".
- Big Good: He fulfills this rule, more specifically in Operation: Z.E.R.O.. He is revealed to be Numbuh 0, the founder of the modern age of the KND Organization. Likewise, he rises up against his evil father, Grandfather (who ruled the world as an Evil Overlord), to save the world. For extra bonus points, he is Numbuh 1's father.
- Big Ol' Eyebrows: His large eyebrows are designed to represent him being blind to the world around him.
- Breaking The Cycle Of Bad Parenting: He might be a Bumbling Dad, but he always tries to be a good father for Numbuh 1. His own father used him and his brother as slave labor.
- Bumbling Dad: Comes off as oblivious and dim-witted due to the decommissioning.
- Cain and Abel: The Abel to Father's Cain. He was good, while Father embraced the dark side due to being too cowardly to stand up to their dad.
- Catchphrase: As Numbuh Zero, Monty is fond of the descriptive phrase "crackerjack".
- Cool Shades: As Numbuh Zero, he wore sunglasses.
- Crouching Moron, Hidden Badass: He's a real nutcase, but underneath his dull wit is a surprising level of competence. This is largely because he was Numbuh Zero, and his current personality is due to his memories of his childhood being erased.
- The Faceless: Initially had his face obscured, but his face was seen from the halfway point of "Operation: O.O.M.P.A.H." onward.
- Heroic Sacrifice: In Operation: Z.E.R.O., he allowed himself to be decommissioned a second time in order to stop Grandfather.
- Morality Pet: Downplayed. He seems to be this to Grandfather, as he does like him as his son and considers him the favorite, but this doesn't mean Grandfather is willing to pull any punches.
- My Hero Zero: He is Numbuh Zero, so of course he's a hero called Zero.
- Parental Favoritism: His brother says his father always favored him.
- Parental Obliviousness: One of the many things that seems to have escaped his notice is that his son is part of a top secret organization.
- Retired Badass: Is the grown up and decommissioned Numbuh Zero, a legendary member of the Kids Next Door who literally saved the entire world.
- Walking Spoiler: He plays such a vital role in Operation: Z.E.R.O. that it's hard to talk about his involvement there and in subsequent appearances without raising spoilers.
Numbuh 1's mother, who is often found by her son to be as embarrassing as his father. Voiced by Jennifer Hale.
- Amazingly Embarrassing Parents: As with his dad, Nigel is embarrassed of her most of the time.
- Back for the Finale: Both she and her husband get recommissioned to see their son being accepted into the Galactic Kids Next Door in "Operation: I.N.T.E.R.V.I.E.W.S."
- Out of Focus: She appears less frequently than Nigel's dad.
- Retired Badass: Like her husband, she's a former Kids Next Door operative. She was once Numbuh 999.
- Unnamed Parent: She isn't given a first name.
Numbuh 2's Family
Numbuh Two's little brother, Tommy is an excitable child ready to fight adult tyranny. Unfortunately, circumstances effectively halted his KND career. He now fights solo as "The Tommy". Voiced by Dee Bradley Baker.
- Badass Normal: Not that Kids Next Door operatives are special in a unique sense usually, but Tommy stands out for managing to beat Father at least twice through outsmarting him (once while still undergoing training), and then holding his own in his focus episodes after losing operative status. All when he doesn't quite have the same 2x4 technological skills of his older brother or the combat capability of most other operatives.
- Bratty Half-Pint: How his initial characterization goes in "Operation: T.O.M.M.Y.", his introduction episode; he teams up with the Common Cold just to have him destroy the Kids Next Door so that Tommy can hang out with his brother. The Common Cold got Tommy too, and he does get better about this as the series goes along but it never quite goes away completely.
- Broken Win/Loss Streak: In "Operation: C.A.K.E.D.-F.O.U.R." he breaks his family's Tube-A-Thon losing streak (Despite his brother coming in dead last...again).
- The Cowl: Parodied. He tries to be an intimidating hero clad in a cape who lurks in the shadows but can't pull it off.
- Crouching Moron, Hidden Badass: Managed to defeat Father on his own in G.R.A.D.U.A.T.E.S;
- A Day in the Limelight: "Operation: D.U.C.K.Y.", "Operation: T.R.A.I.N.I.N.G.", and "Operation: G.R.A.D.U.A.T.E.S."
- Disappeared Dad: No one really knows what happened to him. He may or may not simply be dead.
- Dude, Where's My Reward?: In "Operation: G.R.A.D.U.A.T.E.S.". Justified by the fact that KND computer has fail-safe that bar decommissioned operatives from being re-instated. At least he was able to walk away with his memories.
- Guile Hero: Tommy rarely if ever fights directly, opting for analyzing and thinking up Indy Ploy strategies when push comes to shove, and being surprisingly good at it. Of course, if put directly in harm's way outside of his focus episodes, he never stands a chance.
- Hates Baths: Like many kids his age. Unlike most kids, the lengths he'll go to avoid taking a bath are pretty extreme.
- Heroic Sacrifice: In "Operation: G.R.A.D.U.A.T.E.S.", he willingly removes himself from the Kids Next Door to thwart Father's plan.
- Heroic Wannabe: He wants to be like his brother Numbuh Two.
- Honorary True Companion: He's loyal to Sector V and regarded as an honorary member, more or less.
- I Work Alone: After becoming "The Tommy", he operates independently of the Kids Next Door.
- Keet: Ties in with his Large Ham status, as he is a lot more hyper and enthusiastic than his brother
- Large Ham: Once he becomes "The Tommy", he becomes considerably hammier.Numbuh Five: "I work alone! I am The Tommy!" He is definitely your brother, Numbuh Two.Numbuh Two: (indignantly) Hey, what's that supposed to mean?
- Lower-Deck Episode: "Operation: T.R.A.I.N.I.N.G." is the first episode where he's a major character.
- Nice Hat: As "The Tommy", he wears a cool wide-brimmed aht.
- Nice Job Breaking It, Hero!: Tommy has a habit of doing this, mainly starting with "Operation: T.O.M.M.Y."; because Tommy made friends with the Common Cold, the entire Sector V (save for Numbuh 2) gets captured by the Flu Bug Machine. Numbuh 2's mother fixes everything though.
- Then there's "Operation: E.N.D.", where he takes a moment to mock Numbah Two Seventy-Four (aka Chad Dickson) to his face after his true age was revealed. He gets taken as a hostage for it, allowing Chad the opportunity to try to send the Moonbase into the sun and attempt an escape as it forces the mostly-decommissioned Sector V to improvise saving the day.
- He manages to defeat Father in "Operation: G.R.A.D.U.A.T.E.S", but the way he does so allows Father to take over the KND in "Operation: I.T." How? He placed Father's booger in the Kids Next Door Code Module, thus resulting in his own machine turning him into an animal. But due to a technicality, this also makes him a Kids Next Door member.
- Spell My Name with a "The": He calls himself The Tommy, though he's about the only one.
- Tagalong Kid: Much to everyone's annoyance, he always insists on joining the others on missions.
- You Are Number 6: Played with; He takes the title of Numbuh T during his brief tenure with the KND.
- Mama Bear: She's quick to defend her boys when they're in danger.
- Parental Obliviousness: Surprisingly averted. Mrs Gilligan seems to be well aware of the Kids Next Door, openly scolding Numbuh Two for implementing 2x4 technology into the wiring of the house. She even saves Sector V from the Common Cold using a similar kind of technology.
The father of Numbuh Two and Tommy. He isn't seen in the present day and is only mentioned. Voiced by Jeff Bennett.
- Ambiguously Absent Parent: It isn't clear whether the reason we don't see Numbuh Two's father is because he's deceased or he's simply divorced from Betty.
- The Faceless: While he does appear in the comic story "Operation: T.R.I.K.E." (which took place when his sons were younger), his face is obscured.
- The Ghost: He's never seen, and the time we hear his voice in "Operation: C.A.K.E.D.-F.O.U.R." is clearly just in his eldest son's head.
The grandmother of Numbuh Two and Tommy and the mother of Betty Gilligan. Voiced by Candi Milo.
- Enemy Mine: She and the Senior Citizen Squad help Lizzie get her lunch back from Robin Food in "Operation L.U.N.C.H." and for a good reason. Robin Food and his band of Hungry Men are actually the retirement home's cafeteria workers but are too lazy to make a proper meal, so they steal kids' junk food, much to the seniors' hate.
- I Was Quite a Looker: According to her debut episode, she was pretty cute as a teenager
- Never Mess with Granny: Don't ever get her cross. She may be a senior citizen, but she can still kick your ass.
- Screw Politeness, I'm a Senior!: She's not very nice and tactful.
- Temporarily a Villain: She fought the KND with two friends of hers while they were temporarily de-aged into teenagers in "Operation: T.A.P.I.O.C.A."
Numbuh 3's Family
Numbuh Three's little sister. She's just as cute and cuddly as her sister, if not moreso, but has a hidden dark side. Voiced by Tara Strong.
- Arch-Enemy: She's been hellbent on getting revenge on Numbuh 2 since "Operation: C.L.U.E.S.", when he exposed her crime of killing her sister's Rainbow Monkey during dinner.
- Cain and Abel: The Cain to Numbuh Three's Abel.
- Creepy Child: She's been the main antagonist of 2 very creepy episodes. It fits her character perfectly.
- Cute and Psycho: She's really not all there. Entering her name into the Galactic Kids Next Door ARG website gets the response "that kid is nuts".
- Enfante Terrible: Unlike Numbuh Three, she is not as innocent as she appears.
- FaceHeel Turn: In her first few appearances, she acts as an ally to Sector V, but she turns to the darker side of the battle against adult tyranny when Numbuh 2 exposes her for stabbing one of her sister's Rainbow Monkeys with a fork.
- Girlish Pigtails: They make her look more innocent.
- Grounded Forever: After stabbing Numbuh Three's rainbow monkey.
- Hair Decorations: Her pigtails are held up by yellow pearl hair ties.
- Improbable Weapon User: She flings handfuls of crayons at Hoagie during their confrontation in "Operation: S.P.A.N.K.E.N.S.T.I.N.E". Sounds silly, but somehow they're sharp enough to pierce bullet-sized holes in her bedroom door.
- Laser-Guided Karma: In one episode, she stole Count Spankulots spanking power for her monster Rainbow Monkey. Guess what happened to her when he got it back.
- Mad Scientist: In "Operation: S.P.A.N.K.E.N.S.T.I.N.E", she constructs an elaborate device in her room that drains Count Spankulot's spanking power and injects it into Kuki's dead Rainbow Monkey, turning it into a giant rampaging spanking zombie.
- Meaningful Name: Her name in Japanese means "bug", and she literally bugs Kuki by being an Annoying Younger Sibling.
- Obfuscating Stupidity: She acts even more ditzy than Numbah 3, but only to hide a truly devious and sinister mind.
- Puppy Love: With King Sandy.
- Unholy Matrimony: With King Sandy.
Numbuh 3's grumpy father. Voiced by Keone Young.
- Berserk Button: He prefers cold temperatures and hates it when someone in his house turns up the thermostat. This may be a reference to the fact that most housing units in Japan don't have central heating.
- Drama Queen: In spite of his grumpiness, he can be quite dramatic, as shown by his overreaction to forgetting to put chocolate sauce on the the ice cream sundaes in "Operation: S.P.A.N.K.E.N.S.T.I.N.E.".
- Hair-Trigger Temper: He loses his temper very easily, and even the smallest things can set him off.
- Jerkass: He's usually in a sour mood and always complaining about something. He is also a rude houseguest, as shown in "Operation: H.O.T.S.T.U.F.F." when he ransacks Sector V's fridge and drinks all the triple pop soda while staying at the treehouse.
- Jerk with a Heart of Gold: Still, he does love his family. A montage of Numbuh 3's childhood shows him being a loving father to her.
- Meaningful Name: His name is Japanese for "crab", and he has a crabby personality.
- Must Have Caffeine: Implied. When staying at Sector V's treehouse in "Operation: H.O.T.S.T.U.F.F.", he asks Numbuh 4 several times if they have any coffee.
- Obnoxious In-Laws: Presumably, after he becomes Numbuh 4's father-in-law.
- Ocular Gushers: His reaction to forgetting the chocolate sauce for the ice cream sundaes he was making in "Operation: S.P.A.N.K.E.N.S.T.I.N.E."
- Serious Business: He takes the making of ice cream sundaes very seriously.Kani: Making an ice cream sundae takes CON-CEN-TRA-TION! (smashes ice cream carton against the counter with every syllable) You must have the right ice cream, the best bananas, and the richest chocolate sauce to—I FORGOT THE CHOCOLATE SAUCE! (cries giant streams of tears)
- Sharp-Dressed Man: He always wears a suit and tie.
- Wacky Parent, Serious Child: Completely inverted with his older daughter Kuki being a happy and cheery Genki Girl, while Kani himself has a grouchy and irritable demeanor at all times.
Numbuh 3's stern and serious mother, who is a businesswoman and the boss of Numbuh 2's mother. Voiced by Lauren Tom.
- Dark and Troubled Past: She mentions not being allowed to play with toys as a young girl, suggesting that her parents were very strict.
- Good Parents: She loves her daughters and wants them to have a happier childhood than she did, which is why they have so many Rainbow Monkeys.
- I Never Said It Was Poison: How she figures out that Hoagie ate the turkey in "Operation: C.L.U.E.S."
- Ironic Name: Her name means "energetic", but she is very stoic and calm.
- Not So Stoic: Her stern facade briefly cracks when she shows sadness about her unhappy childhood in "Operation: C.L.U.E.S."
- Prim and Proper Bun: Always wears one as part of her serious personality.
- Significant Double Casting: Shares a voice actress with Kuki, her older daughter.
- Wacky Parent, Serious Child: Again, inverted—her daughters are Genki Girls, while she is stern and strait-laced.
- Women Are Wiser: Genki appears to be calmer and more reasonable than her husband Kani. In "Operation: S.P.A.N.K.E.N.S.T.I.N.E.", while Mushi is grounded, Kani yells at her for making too much noise, and Genki calms him down by reasoning that the least they can do is let Mushi play in her room while she's grounded.
Numbuh 4's Family
Numbuh 4's baby brother, a dodgeball prodigy. Voiced by Dee Bradley Baker.
- Blinding Bangs: Same hairstyle as his older brother.
- Brainy Baby: Despite being only a baby, he is already Famed In-Story as the greatest dodgeball player in the world.
- I Have Your Wife: In "Operation: D.O.D.G.E.B.A.L.L.", he is held hostage along with his parents in order to lure Numbuh 4 out so the Dodgeball Wizard can defeat him.
- Meaningful Name: "Joey" is an Australian slang word for various baby marsupials.
- Morality Pet: Wally is extremely protective of him.
- Pintsized Powerhouse: As seen in his fight with the Dodgeball Wizard in "Operation: D.O.D.G.E.B.A.L.L.".
- Significant Double Casting: Joey and his brother Wally are voiced by the same actor.
- The Unintelligible: He only speaks in Baby Talk, but Numbuhs 2 and 4 can perfectly understand him.
Numbuh 4's father. Voiced by Jeff Bennett.
- Good Parents: In "Operation: M.A.T.A.D.O.R.", he signed up for what he thought was a seminar on "How to Be a Better Dad". Too bad it was actually a trap that lured in adults to use them as bulls in a fighting ring.
- I Have Your Wife: In "Operation: D.O.D.G.E.B.A.L.L.", he is held hostage with his wife and youngest son Joey in order to lure Numbuh 4 out so the Dodgeball Wizard can defeat him.
- Long-Lost Relative: The 19th issue of Cartoon Network Action Pack reveals in the story "Operation: H.I.S.T.O.R.I.E." that the Toiletnator is his long-lost twin brother.
- Meaningful Name: Sydney is a city in Australia.
- Parental Obliviousness: He tends to be comically oblivious to whatever danger is going on around him.
- In "Operation: D.O.D.G.E.B.A.L.L.", he is being held hostage by the Dodgeball Wizard with his wife and younger son (as in, they are literally tied to a post), and he thinks it's just a magic show.
- In "Operation: S.P.R.O.U.T.", he completely fails to notice a giant KND vehicle busting through the wall of his house.
- Strong Family Resemblance: He has the same blonde hair and bowl-cut hairstyle as both of his sons. However, he does not have Blinding Bangs like them.
Mrs. BeetlesNumbuh 4's mother. Voiced by Jennifer Hale.
- Demon Head: Her face becomes demonic when she angrily warns her oldest son not to break her last priceless vase in "Operation: B.R.E.A.K.U.P."
- Parental Obliviousness: Like her husband, she tends to be comically oblivious to whatever danger is going on around her, thinking that her family is seeing a magic show when the Dodgeball Wizard kidnaps them in "Operation: D.O.D.G.E.B.A.L.L." and not paying any mind to the giant KND vehicle bursting through their house's wall in "Operation: S.P.R.O.U.T."
- Unnamed Parent: Her first name is never revealed.
Numbuh 5's Family
Numbuh 5's mother. Voiced by Cree Summer.
- The Faceless: Her face is never seen.
- Living Prop: She doesn't do much of importance and mostly just exists to avert Invisible Parents.
- Parental Obliviousness: She has no idea that her daughters are always fighting.
- Significant Double Casting: She shares a voice actress with both of her daughters.
- Unnamed Parent: Her first name is never revealed.
Numbuh 5's father. Voiced by Kevin Michael Richardson.
- Amazingly Embarrassing Parents: In "Operation: S.U.P.P.O.R.T." he mentions his older daughter Cree using a training bra in front of Numbuh 1 and Numbuh 2. She reacts with appropriate shock and horror.
- The Faceless: Whenever he is present, his face is always out of frame. His character model, as revealed by behind-the-scenes material, reveals he never even had eyes drawn.
- No Celebrities Were Harmed: Dr. Lincoln is a shameless parody of Bill Cosby.
- Non-Ironic Clown: His previous job before he became a doctor, as revealed in "Operation: C.L.O.W.N."
- Parental Obliviousness: Like his wife, he has no idea that his daughters are always fighting.
- Unnamed Parent: His first name is unknown.
Numbuh One's demanding girlfriend. While she's quite clingy, she does genuinely care for Nigel, but his work for the Kids Next Door strains their relationship.
For information on her true identity, see this page.
Voiced by Grey DeLisle.
- Accidental Hero: In "Operation: D.A.T.E.", fed up with Numbuh One not paying attention to her during the Delightful Children's party, she tries to throw a cup of soda at his face but accidentally drenches the fuse box instead, shorting it out and blowing up the entire building, ruining the DCFDTL's evil plans for the night. Though with The Reveal that she is actually a Galactic KND operative, it may not have been accidental at all...
- Badass Normal: Presented as such throughout the series, though her true identity makes this a subversion.
- Characterization Marches On: In her first appearance, she brainwashed Nigel into being her obedient boyfriend and even tried to make him destroy his friends. The KND fight back and Nigel is unbrainwashed, but the episode ends with Lizzie getting the date she wanted anyway. Later episodes more or less completely ignored her origin story and considerably softened her character.
- Clingy Jealous Girl: Towards Nigel. So much that in her first appearance she tried to permanently brainwash him to abandon his friends in favoring of becoming her personal boyfriend slave.
- Day in the Limelight: "Operation: L.U.N.C.H." and "Operation: L.E.A.D.E.R.". The first half of "Operation: P.O.O.L." has her sharing the spotlight with Nigel.
- Easily Forgiven: Nigel and the rest of Sector V had no hard feelings over the little matter of her having originally tried to brainwash him. Though it's mostly Numbuh One and Numbuh Three. Numbuh Two and Four openly dislike her, dreading any contact with her at all. They just don't verbalize it much due to fearing her bad temper (at least Numbuh Two fears her temper). Numbuh Five is tolerant of her at best.
- Eye Glasses: Similar to her boyfriend.
- Fat Girl: She's about as rotund as Numbah 2.
- Fiery Redhead: Fiery is one way of putting it...
- Foreshadowing: Her real identity is foreshadowed throughout the series.
- In "Operation: L.U.N.C.H.", Lizzie takes the fight to the Robin Food group with a K.N.D. giant locker robot, and in "Operation: P.O.O.L." she was also one of the operatives of the "Destructively Nefarious Kids".
- There's also multiple times late series that demonstrate she seems to be more savvy than a civilian probably would normally be about some of these things.
- I Want My Beloved to Be Happy: She and Numbuh One eventually break up when she realizes the world needs him more than she does, and that his first loyalty will always be to the Kids Next Door.
- Hair-Trigger Temper: Some moments show her getting VERY angry.
- Jerk with a Heart of Gold: Lizzie may be bossy and abrasive, but she cares about Nigel and shows that she can rather be polite to the KND.
- Lethal Chef: She can make a soup that doubles as a hand grenade strong enough to blow up a school. Not helping things is that she won't listen to others who criticize her cooking (to be fair said criticizing is almost entirely through insults) and that she herself actually finds the food she makes to taste good.
- Let's Get Dangerous!: When she's properly motivated (either by Numbuh One being in danger or her plans being interrupted one too many times), she's a mecha-commandeering force to be reckoned with.
- The Load: She's not an operative - or at least, she doesn't claim to be. Subverted when she proves to be capable of handling herself in certain situations such as "Operation: C.A.K.E.D.-T.W.O.", "Operation: P.O.O.L.", and "Operation: D.A.T.E.".
- No Indoor Voice: Good lord is she a loudmouth. In "Operation: Q.U.I.E.T." she even pulls a megaphone out of nowhere to try and wake up Nigel in the middle of the night so they can go on a date.Lizzie: (yelling into the megaphone) NIGEL! WAKE UP! I HAVE BEEN PLANNING THIS DATE SINCE— (Numbuh 3 jumps headfirst into the megaphone)
- Official Couple: Her and Numbuh One. They break up later, and she is the one who brought it up.
- Only Known by Their Nickname: She's known as "Lizzie" to everybody. Though it's likely not her real name, it's presumably short for something...
- Palette Swap: She has the same physical appearance as one of the Delightful Children From Down The Lane (Which is lampshaded in "Operation: C.A.K.E.D.-T.W.O.").
- Puppy Love: With Numbuh One.
- Single-Target Sexuality: As she puts it, "My heart only belongs to Nigel."
- Tsundere: Type A and hard, sometimes dipping into yandere-ish tendencies in her more extreme moods.
A pilot in shades, The Kid is a rival pilot of Numbuh Two, and Numbuh Four's rival for Numbuh Three's affections. Voiced by Carlos Alazraqui.
- Always Someone Better: A superior pilot and engineer compared to Numbuh Two. It's unclear whether he actually is one or just using better equipment (he goes down pretty easy once Numbuh Two disables his Deflector Shields and it's easy to call the hit that took him down in that fight a lucky one).
- Cool Shades: Meant to be reminiscent of a "Top Gun" style character, in contrast to Numbuh 2 resembling an old-school flying ace.
- I Work Alone: Numbuh Two tries recruiting him into the KND after seeing his skills, but he turns down the offer down for this reason.
- No Name Given: He's officially credited as "The Kid", and no one ever calls him by any name in-series. Fanon calls him "Ace", due to Mr. Washer referring to him as such.
- The Rival: To Numbuh Two. It turns into a Friendly Rivalry after they realize they were being manipulated into fighting each other by Mr. Washer.
- Romantic False Lead: In the Numbuh Three/Numbuh Four pairing.
- You Know What You Did: In "Operation: D.O.G.F.I.G.H.T." He blames Numbah 2 for destroying all of the chili dog factories in town. Unbeknownst to him, Numbah 2 is only after him for the sake of his own pride, and the true culprit is Mr. Washer.
A former KND agent (Numbuh 9) who is decommissioned when he turned 13. However it's revealed he's part of a secret sect of teenagers who are still loyal to the KND and doing undercover work to help them from behind the scenes. Voiced by Khary Payton.
- 100% Adoration Rating: He was very popular among the KND organization for being one of the best, kind, and his promise to tackle the source of the Chicken Pox epidemic. Even his decommissioning was heartbreaking for those who had to witness it including with Numbuh 86. It's a good thing his results didn't go unnoticed due to his new role for the KND after turning 13.
- The Ace: One of the KND's top-ranking operatives; Numbuh Five calls him "the best there is". And valued enough to be kept on duty even after his 13th birthday, as a spy.
- Cool Big Bro: While part of the KND, he was a beloved friend to Sector V, particularly to Numbuh Five. She misses him dearly, and is overjoyed to find out that he wasn't actually decommissioned, still remembers her, and is in fact still working for the KND, as a spy.
- The Dreaded: The Galactic KND considers him "highly dangerous".
- Face Death with Dignity: When Maurice turns 13, he accepts his decommissioning and the loss of his memories. Note that Maurice is the only KND agent show in the series who accepts his decommissioning, where others betray the Kids Next Door when they turn or before they turn 13 years old. Because Maurice accepts his decommissioning, he is rewarded with his reputation and legacy being left intact, with all of his former teammates and fellow operatives sending him off with honor. Note that even Numbuh 86, a boy hater and Head of Decommissioning, treats him with respect and is sad to see him go. It is implied that because he loyally accepts his fate, he is allowed to keep his memories and become part of a secret sect of teenagers who are still loyal to the KND and do undercover work to help them from behind the scenes.
- Fake Defector: He is in fact part of the Teens Next Door.
- Karmic Jackpot: Maurice. Because he accepts his decommissioning and the loss of his memories, he is rewarded with his reputation and legacy being left intact, with all of his former teammates and fellow operatives sending him off with honor. He also is allowed to keep his memories and become part of a secret sect of teenagers who are still loyal to the KND and doing undercover work to help them from behind the scenes. Meaning that he is also able to keep his promise to track down the source of the chicken pox used by the teenagers and destroy it.
- Nice Guy: Very popular with the K.N.D for his personality. His decommission is quite heartbreaking for the organization.
- The Promise: During his younger days two of his fellow operatives get hit with Chicken Pox despite the mission being a success. He vowed he was would track the source of the chicken pox used by the teenagers and destroy it. He never manages it during his tenure with the K.N.D but after being decommissioned and turning mole for the group he does fulfill his promise.
- Reality Ensues: Subverted. It at first appeared that his acclaim and trustworthy nature didn't keep him from being decommissioned, despite Numbuh 86 and 362 both appearing very sad in having him so. But it turns out it actually had and he was instead moved to another, little-known section of the KND for the most skilled and trustworthy operatives called The Teens Next Door which spies on teen meetings to gather information for the KND.
- Reverse Mole: He was never truly decommissioned and his typical teen attitude is all an act so he can spy on the teens for the K.N.D
- Fountain of Youth: She's been in 5th grade for decades thanks to having found one of these in an ancient temple beneath the school. She has to keep drinking from it regularly, otherwise she'll quickly return to her natural age.
- He Knows Too Much / Ungrateful Bastard: After the Sector V saver her from The Delightful Children, she tries to kill them because they know about the Fountain of Youth.
- Never Grew Up: She's ancient, but she still acts like a 10-year-old.
- Really 700 Years Old: Exactly how old is never specified, but definitely more than 300 years old.
- Speech Impediment: Because she has been a kid for so long and never took off her braces, Leona cannot articulate properly always spitting and stuttering when she talks as well as saying "th" instead of "s".
Numbuh 4 and Numbuh 5's homeroom teacher at Gallagher Elementary School. Voiced by Jennifer Hale.
- Cannot Tell a Lie: Owing to her role as a teacher, she'll always give an honest answer to any question asked of her, only to quickly follow up with "I shouldn't have said that!" when she realizes she's divulged too much. Numbuh 4 of all people has exploited this multiple times for pop quizzes and then to discover how to cure Were-Dogism.
- Chekhov's Gun: In Operation H.O.U.N.D. she doesn't want Numbah 4 to share his project aloud because she just ate. While it seemed like an innocuous comment on his poor work, it's actually a hint at her Weredog nature as they are disgusted by poor-homework.
- Evil Teacher Only due to the were-dog necklace. She gets better once it is removed.
- Foreshadowing: In her first appearance in Operation H.O.M.E.W.O.R.K., she's wearing a ring on her finger hinting that she's married. When she reappears in Operation H.O.U.N.D., she's no longer wearing it.
- Hot Teacher: Numbah 4 has a not-so-subtle crush on her for this reason.
- The Man Behind the Man: The leader of the Were-Dogs.
- No-Sell: She reveals that bad homework can't stop her, as she easily eats 4's terrible papers with a laugh. It's odd considering she expressed disgust at the very same work in a previous episode, though maybe she just grown used to it.
- Wolf Man: Due to a curse she gained after being given a cursed green necklace by her angry ex-husband.
- Woman Scorned: Gender-inverted. She was given the were-dog curse by a necklace from a bitter ex-husband.
A former accountant and now tie hunter that Numbuh One befriends in "Operation: K.N.O.T." Voiced by Jim Cummings.