List of Jimmy Neutron characters

This is a list of all The Adventures of Jimmy Neutron: Boy Genius characters.

Main characters

Jimmy Neutron

James Isaac "Jimmy" Neutron is the main character of the show. He is a 10-year old genius inventor whose inventions often go awry and generally cause massive damage to the town, annoy the inhabitants of Retroville, or cause a situation which brings a near-extinction of mankind. These situations call for Jimmy to find a way to fix the problem he caused, and usually it's up to him to save the day against his own creations. He often uses sudden surges of thought which he calls Brain Blasts. His name is a spoof of the scientist Isaac Newton. His mother refers to him by his full name as James Isaac Neutron only when his inventions cause disasters.

His amazing inventions include:

self-folding pants that put themselves away
hi-tech binoculars
his robotic dog Goddard
a Cheese Ray that can transform things into cheese
a time booth for traveling to the past (constructed from a phone booth)
tiny talking robots invented from the same chip used to make the self-folding pants
a translator that can be used to communicate with fish
Neutronic air gum that allows one to breathe underwater
gum that allows one to memorize an entire book by chewing it
the JimmyBot
candy that uses every possible pleasure taste bud
a brain drain machine that can adjust an IQ level from Albert Einstein to drool-monkey
a jetpack
a motorized tire
a mini-submarine
a flying rocket as well as a flying land/sea hover-car
a giant machine known as the Neutronic Game Pyramid that can insert people into their favorite video games
BroBot
BroBot's Parents

He has an extensive laboratory below his clubhouse which is accessed via hair DNA scan. Carl Wheezer and Sheen Estevez are his best friends. Although he isn't an Ultra Lord fan, like Sheen, Jimmy has his own action-hero that he looks up to, the super-spy guy named Jet Fusion, who stars in many movies shown in the Retroville Theater and actually is a real spy whose movie titles are arguably spoofs of 007 fame.

Jimmy has a crush on Betty Quinlan (refers to her as "the most beautiful thing in the world") and Cindy Vortex (Jimmy loves her and vice-versa, and has referred to her as "kinda pretty" and "farther than a bowling ball", both on occasions where his brain has been taken. Then in King of Mars, he openly admits "I just think you're pretty smart...and you smell nice,....and you kind of distract me...sometimes.), the latter of which he denies, although at the end of episode 55, Lady Sings the News, Jimmy kisses Cindy on the lips and walks away. He is voiced by Debi Derryberry.

Goddard

Goddard is Jimmy's robotic dog, equal parts useful tool and best friend. Goddard is one of Jimmy's very few successful inventions. He can do many things, including blow up and re-assemble himself after being told to "play dead". When Jimmy is in trouble, Goddard gives his suggestions on a screen on his chest. The two first are always the most outrageous, but the third and last is always the one that Jimmy will follow. Goddard is voiced by Frank Welker and various others, and named after rocket pioneer Robert Goddard (scientist). Hugh says Goddard can do 11,000,004 things, except clean up after himself, which is really a hobby for him. He has a first-aid kit.

Carl Wheezer

Carlton Ulysses "Carl" Wheezer is Jimmy's neurotic, Llama-loving friend. According to canon, Carl was born in 1992. He is ten years old. Carl is known as nervous, timid and suffering from hypochondria; at times, he tries to overcome these personality traits in order to appear "cooler" around Jimmy and mutual friend Sheen Estevez. He has many talents, the most recognizable is his phenomenal singing, with the hit-single, "Folding and Hanging", among other pieces such as "Singing and Sitting". Carl also appears to be in love with Jimmy's mother, Judy Neutron, accidentally saying that she's beautiful around Jimmy and Sheen, and carrying around a picture of Jimmy's parents with his head pasted over Jimmy's dad's.

When his parents expanded their cable line-up, Carl found himself focusing on a channel devoted to llamas and a show about a singing and flying super-hero crossing-guard called Llama Boy; he has adored them ever since, going so far as to join a fan club, the Llama Love Society. He is allergic to just about everything, perhaps including Llamas, much to his disappointment. His blood type is O Negative. Carl Wheezer has a sensitive scapula. Carl and his parents are voiced by Rob Paulsen. His birthday is January 17th.

In the episode Normal Boy, it's revealed that Carl is the inventor of the "Hot Dog Holder Deluxe", also known as the versa-bun (which is a normal hot dog bun that he didn't really invent). It is revealed in "The Incredible Shrinking Town" that he took ventriloquist lessons, he can virtually imitate and sound just like everyone. It is also hinted that he has some sort of dislike for Sheen. For example, when Brobot said "I don't like Sheen", Carl replied, "tell me about it. Also, when they were trapped in a submarine, Sheen declared he did not want to eat Carl, and Carl replied, "Well I'm not going to eat you either! Okay, maybe just a nibble."

Cindy Vortex

Cynthia Aurora "Cindy" Vortex is Jimmy's semi-sassy mouthed, emancipated rival who is skilled in both the fine arts of Tai Chi and Tae Kwon Do and a right hook. One thing that terrifers her is mimes. Although she is not exactly an inventor (except for her "Sweat Socks Transmogrifier"), she can build 'chocolate volcanoes that engulf the helpless gumdrop citizens of Pompeii', with ease.

Cindy, in stereotypical "girl" fashion, schemes to be popular, as seen in Out Darn Spotlight, and used to be the town's resident genius prior to Jimmy's arrival (perhaps she calls him "Nerd-tron" out of jealousy?). She is almost a match for Jimmy's intellect, and although he surpasses her in his knowledge of science, she often keeps up with him in other areas, such as singing, art, acting, and poetry. Whereas Jimmy has a robotic dog, Cindy has a real one.

In episode 2/2 {Birth of a Salesman} Cindy "owns" Jimmy after "buying" him at an auction for $2.00! She's obviously in love with Jimmy, but treats him like dirt to hide her true feelings (similar to Helga G. Pataki of Hey Arnold!). Jimmy returns these feelings, but he tries to cover them up just the same. Cindy usually calls Jimmy "Nerdtron" or some other such name. She also ruins Jimmy's good moments on occasion (the end of The Incredible Shrinking Town). Cindy almost proclaims her love for Jimmy twice, first in The 'N' Men, (upon which she faints due to losing energy from the mutation) and in The League of Villains where Jimmy kisses her on the cheek and she shows signs of being love-struck. A time that truly reveals their love is at the end of episode 55, Lady Sings the News, when Jimmy kisses Cindy on the lips and walks away. Another time Jimmy kissed Cindy was in I Dream of Jimmy, when Jimmy was stuck in Carl's dream and the only way Jimmy could convince Carl to wake up was to kiss Cindy. Later Cindy comes over furious to Jimmy's house to give him a smack across the mouth and proclaims "Not even in his dreams Neutron".

In Trading Faces when Jimmy's latest mind-reading invention short circuits and causes Jimmy and Cindy switch minds. Later when the process is reversed Cindy remarks about how their minds had mixed and one of them was imagining the two of them walking down a country lane, holding hands, and kissing. Jimmy admits to remembering that, but denies being the originator of that thought. Cindy also denies, and the two argued. In Stranded, it is revealed that nobody knew that Cindy knew Jimmy's real name. In The King of Mars, Cindy goes out to get Jimmy's attention, by putting on Perfume. During the episode Cindy wears her new flying suit and manages to get Jimmy's attention. Later in that episode, Jimmy admits that he only pretends to ignore Cindy and says "I just think you're pretty smart and...you smell nice...and you kinda distract me...sometimes"(referring to Cindy). In My Big Fat Spy Wedding when Jimmy walks up to the church in a tux, Cindy refers to him as a "Hunk... muffin!", calls him "James", and then later records herself saying he was handsome on camera but later rewinds and records over it.

In the hour long crossover special, The Jimmy Timmy Power Hour, Cindy develops feelings for Timmy Turner which continues in the sequel and upsets Jimmy. Her romantic responses to Timmy stem from the fact that he represents everything to her that she wants to obtain from Jimmy (i.e. attention, consideration, and courtesy). In the second power hour, she becomes angry at Jimmy for blowing her off, so she forces herself to like Timmy even more. Even though she loves Jimmy and only likes Timmy, she revels in the attention of two guys and hence doesn't want to make a decision. According to director Keith Alcorn, the two power hours should be viewed "out of continuity with the rest of the series." If it were to have a fourth season, Cindy would easily end up with Jimmy. If Jimmy admitted that he loved her, Jimmy would no longer serve a purpose to her. Recently she seems to be becoming a very slightly more gentle mellowed out character and has picked on Jimmy a bit less. Her birthday is June 5th. Cindy is voiced by Carolyn Lawrence.

Sheen Estevez

Sheen Juarerra Estevez is Jimmy's hyperactive heroic friend; he is 12 years old, making him 2 years older than Jimmy and Carl. The three are in the same school grade because Sheen was held back twice. Sheen's wardrobe largely consists of a green t-shirt and jeans. The t-shirt depicts UltraLord, a popular superhero within the show that Sheen is obsessed with. Sheen is of Mexican ethnicity, he has the type of accent that sometimes sticks with Spanish-speaking individuals after completely adopting English. He speaks Spanish once in a while (In the Mexican Spanish dub of the series, he speaks Spanish with a Japanese accent).

Like many other animated characters, Sheen rarely changes his clothes and always wears an Ultra Lord T-shirt to show his devotion and loyalty to his favorite super hero whom he looks up to as a role-model. Not surprisingly, Sheen wrote the entire Ultra Lord website on the Internet. Sheen has the largest Ultra Lord action figure collection in all of Retroville, and is extremely offended if someone refers to them as "dolls". Sheen was once sent into his favorite Ultra Lord video game, and he got to do battle with Ultra Lord's arch enemy, Robo-Fiend, with help from Jimmy Neutron. Carl Wheezer controlled Robo-Fiend in the Lab for a brief period of time, not realizing that Jimmy and Sheen were really in the game, then decided to play a llama video game, saving Jimmy and Sheen with a huge thunderstorm of llamas. Thankfully, the evil Robo-Fiend was allergic to Llama milk.

Sheen knows some kung-fu, but he can't win a fight without the proper training of Jimmy's "Ultra-Shock Dance Teacher 8000", a device that dictates his body movements to make use of the proper techniques and moves.

Sheen appears to like guacamole bars, as shown when he was running for class president. Sheen is a member of an "Action Figure Support Group". Although Sheen seems fearless, he is scared of one thing, the crawl-space under Granny's house. Sheen is usually seen on the show tagging along with Carl, as they are best buds in most of the episodes much like the friendship between Cindy and Libby. Sheen is quite educated in the realm of restaurant terminology and slang, as seen in the episode Men At Work. Sheen has abilities with monkeys and can summon the Atomic Monkey Special Forces Squad whenever he wants to. He also has a huge and developing crush on Libby, which seemed to begin after her hair makeover.

The character of Sheen is best known for his hilarious hyperactive manic behavior, and overbearing tone of voice. Sheen is always depicted as unusual and eccentric, often saying very interesting but strange phrases. In the episode Beach Party Mummy it is suggested that Sheen might be on some form of medication and/or medicine (possibly ADD, since he is hyperactive and has a really short attention span). Usually when sitting at a table with the whole gang, he suggests that they play "Spin the Bottle", hoping to be kissed by Libby.

The name "Sheen Estevez" appears to be a reference to the Estevez family of actors — specifically the three members: Emilio, Ramón and Carlos (the latter two use the screen name Sheen). Sheen is another fan favorite, and like Hugh, has his own fan-listing. The character Sheen is known as Max in the German dubbed version of the series. , who also won an Annie award for the role. His birthday is November 19th.

Sheen sometimes fails to grasp the reality of things. For example, in Win, Lose and Kaboom, Sheen is told that if he loses, Earth will be destroyed; he ignores that and is excited to get a car if he wins. In another example, when told that the doomsday is coming, Sheen is only upset when he realizes the Monster truck rally would have been held after Doomsday! Sheen is optimistic and only speaks negatively when he's trying to depress Carl. He usually does this by scaring him, yelling at him, or talking about llamas dying horribly. ("And Carl's Llamas fall down, down into the sulfurous mud pits! How the snake god will be pleased!")

Another fact about Sheen is that he is the only main character without a mother present; Sheen lives with his father and grandmother (although referenced often by Sheen himself, his grandmother has not been seen in the series). Creators of the show have revealed that this is because Sheen's mother died when he was very young. He does, however, have a little sister, as mentioned in I Dream of Jimmy when he talks about a fight he had with her about the 'Potty Fairy'. The name and age of the sister is unknown, and she's never been seen in the movie or television series. Sheen is voiced by Jeff Garcia who uses the same voice when playing Pip in Back at the Barnyard.

Libby Folfax

Liberty Danielle "Libby" Folfax is Cindy's best friend and eventually Sheen's girlfriend. She is African American, and she loves music and experiences withdrawal when not constantly exposed. Pretty intellectual, and loves electronic gadgets. Related to Egyptian Queen Howsaboutislapya (pronounced "HAWS-uh-bot-uh-SLAWP-yuh), as seen in the episode Beach Party Mummy, where she received a brand-new hair makeover to look like the Queen of the Nile, which she still has. She is 11 years old (Turns 11 In The Tomorrow Boys). Libby listens to only the funkiest music. She can play the piano as seen in My Big Fat Spy Wedding. She mostly returns Sheen's interest in her, but only when he's not annoying her with his overbearing mentions of Ultra Lord and his occasional flirting. Voiced by Crystal Scales. Her birthday is December 11th. Libby sometimes joins Cindy in teasing Jimmy, but she has full knowledge that Cindy and Jimmy love each other. She is the only one of the main characters who has a sibling that has appeared onscreen; her little brother appeared in the Father's Day episode, Make Room for Daddy-O. Along with Cindy she won a first place trophy for riverstomp dancing at the School contest; Jimmy, Carl, and Sheen almost beat the girls with Jimmy's electronic rock music guitars and drums but at the last minute the boys destroyed their own instruments in a jealous quarrel and the only thing they ended up with was an eighth place trophy, when there were only seven acts.

Judy Neutron

Judy Neutron is Jimmy's mother. Smart and full of common sense, she is amused with the many antics of her husband. Like a typical mother, she is often preoccupied with tidying up and usually is concerned when Jimmy is off adventuring, of which Hugh is usually oblivious and unaware of, often lamenting the fact her son is such a genius. She sometimes dusts the front lawn, which is quite terrifying. She is also an unofficial grease monkey and is very knowledgeable with machines. In the early episodes, it was hinted that Judy was a genius like her son and thus where he gets his intelligence from. An example occurred in one of the first episodes, "See Jimmy Run", when she correctly and accurately predicted how Jimmy's invention- supercharged running shoes- would fail. Judy is voiced by Megan Cavanagh.

Hugh Neutron

Hugh Beaumont Neutron is Jimmy's father. He is completely oblivious to the fact that his son is a prodigy and is rather childish at times. He also loves his wife, Judy and her cooking, especially her pies. He calls Judy, Sugarbooger. He is otherwise a typical father and always has a piece of advice for him. Hugh has dumb relatives, so Jimmy's genius is most likely not inherited paternally (this has not been confirmed, however). In "Cousin Clash" it's revealed that most of Hugh's relative look like him (including the women!).

Like many of the Neutron characters Hugh has his humorous obsessions, such as pie, butter pats, puppets, and ducks. He invented a holiday based upon pie, known as Pule (Combination of pie and Yule). At a young age, he was an Acorn Lad scout. Hugh always tries to relate his childhood experiences to Jimmy's, but they are often much stranger such as being banned from the school science fair because he burped the table of elements.

One of Hugh Neutron's favorite things to do is collect antique duck decoys, and display them around the house, he occasionally decides one of them is his favorite, but loves them all equally. Hugh has a puppet named Flippy, and is a former toy inventor. He's currently a car salesman and truly enjoys cleaning up Goddard's Lug-Nuts. Hugh also has an interesting taste in family vacations, such as visiting the world's largest underground parking structure, as can be seen a photo of, in the Neutron Family Album. Hugh was given the esteemed name of Towel Boy in Junior High. Hugh Neutron is a fan favorite almost at the level of Jimmy himself. He is voiced by Mark DeCarlo.

Ms. Fowl

Ms. Winifred Fowl is a 5th grade teacher at Lindbergh elementary school. Attracts the oddest men: danced with President Calvin Coolidge, once dated Thomas Edison after Jimmy brought the famed scientist to the future, also claims to have married a werewolf, this is a reference to ads called I Married (insert monster here) and a reference to insults about bad husbands. She used to be in the rodeo before she became a teacher. Resembles a large bird both in her hooked nose and tendency to squawk, hence the name. In one instance (The episode: "Substitute Creature"), Jimmy brought a million year old spinach plant that he mutated from a leaf stuck between a dinosaur's teeth. Jealous of all the attention Cindy received for her beautiful and fragrant flowering plant, his project is presented hastily and little seed pods burst from the plant, and fly into Ms. Fowls mouth. The result is a 50-foot plant-like woman...and lots of trouble for Jimmy. She is voiced by Andrea Martin. Her birthday is June 8th.

Nick Dean

Nick Dean is the "cool" kid at school. Often seen on a skateboard, doing dangerous tricks. He doesn't do show and tell, and is obsessed with styling his hair. Breaks his leg from time to time on his skateboard, when he does so he usually lets out a high pitched girly scream. He was originally going to be part of the regular gang; (In the movie he had that role more than Libby) and Libby would be one of the supporting kids such as Butch or Oleander. He can also sing operatic German, and can style his hair without using his hands. Voiced by Candi Milo.

Minor characters

Minor characters in The Adventures of Jimmy Neutron: Boy Genius are listed below:

A

Aunt Amanda, Jimmy's aunt, she hates Jimmy Neutron because he brings danger to the town. Appears only in the episode "Clash of the Cousins."
April The Gorlock has had one appearance on the show in the episode "Win, Lose, or Kaboom." In fear of her planet's safety, she had performed a seal of trust with Jimmy which resembled a kiss. Cindy had observed this and was insanely jealous. Jimmy's hormones had kicked in after that, and he had hoped for another kiss from her when the adventure was over. He and April would send messages via space rock after that. Her real name is Chee Aaaaaaaaaah Doik!, but she hates this name and threatens anyone who calls her by it.(Voiced by Alyssa Milano)

B

Baby Edward "Eddie" Neutron, Jimmy's infant evil genius cousin, whom looks identical to Granny Neutron as an infant. According to himself, Eddie is a lot smarter than Jimmy and he's only over a year old ("Just wait 'til I hit puberty!") Eddie is voiced by Mark DeCarlo. (appears in Clash of the Cousins, and The League of Villains)
Beautiful Gorgeous, an evil villainness whom is the daughter of Jimmy's enemy, Professor Calamitous. She is voiced by Wendie Malick (appears in Operation: Rescue Jet Fusion, My Big Fat Spy Wedding', and The League of Villains).
Banjo Playing Boy, a boy who plays the banjo. He lives in a tree near the prison (appears in Who Framed Jimmy Neutron?).
Betty Quinlan, Jimmy's first crush who makes Cindy extremely jealous. She is nice to him, and can make him do things he normally wouldn't do. Betty told Cindy that she's fully aware of Jimmy and Cindy's feelings for each other, and to "Just relax and keep out of my face. He's all yours." (Appears in Party at Neutron's, Out Darn Spotlight, One of Us, The Vanishing Act, and brief appearances on My Big Fat Spy Wedding, Attack of the Twonkies and The Jimmy Timmy Power Hour 2: When Nerds Collide.) Quinlan is voiced by Kath Soucie.
Bolbi Stroganovsky, also known as the "boy from fairy-tale land",is the weird resident exchange student from Backhairistan. He normally speaks broken English, but has a surprisingly good Shakespearean acting voice (but only when auditioning). He is voiced by Phil LaMarr. He appears as a medieval peasant and speaks in a vaguely Russian/Czech accent, and went with Jimmy, Carl, Sheen, Cindy, and Libby to the game show in Win, Lose, and Kaboom (by accident) and was even considered from a Species Unknown by the production staff of the game show. He voted himself off of the team in a Survivor-esque squence, thinking he was going to win a prize. He states that "Super-Kaboby Man" is the most famous hero of Backhairistan. It is known that he has a sister in Crouching Jimmy, Hidden Sheen.
Bonzilla, a 10 inch tall reptilian beast in Japan. Bonzilla is a spoof of Godzilla, Bonzai style. He makes two appearances, one in Retroville 9, and one in Win, Lose and Kaboom. In Retroville 9, he is visited by the Retroville 9 after losing to another team in Japan. Sheen insults Bonzilla, resulting in him being burned into a crisp by Bonzilla's fire breath. In Win, Lose and Kaboom Bonzilla is a member of the audience.
Britney, A friend of Cindy, Libby, and Amber, who is also a back up dancer with them. She wears a pink and white tank top with her belly button revealing, a pink jacket, pink pants, and light brown shoes. Her hair is in braided in pigtails that resembles Heidi and her eyes are bluish gray. Britney usually appears as a background character but occasionally hangs around with Cindy and Libby. Britney is voiced by Candi Milo.
Brobot, Jimmy's robotic brother who lives on the moon with robotic parents Jimmy made to get rid of him. Voiced by Paul Greenberg (appears in episodes Brobot, The Junkman Cometh, The League of Villains).
Bueford Lee Stormshuckle, the warden of a correctional facility who framed Jimmy for a bank heist. After Jimmy proved to the police Stormshuckle was the real bank robber, Stormshuckle was fired and arrested. He is voiced by Bill Farmer (appears in Who Framed Jimmy Neutron?).
Burp Boy, Carl's superhero form. His power is that his burps are sonic (voiced by Rob Paulsen) (appears in The 'N' Men).
Butch Pakovski, the slightly slack jawed bully who fears big words, voiced by Rob Paulsen. Butch has a little brother.
Blix, Eustace Strytch's assistant, who always keeps him company. When Eustace Strytch is upset, Blix lets him kick his butt (voiced by Billy West). He appears in the episodes Billion Dollar Boy, King of Mars and My Big Fat Spy Wedding.

C

Carl Sheenster, Jet Fusion's fitness instructor, mentioned in Operation: Rescue Jet Fusion.
Carlman, a boy who once owed Sheen 2 dollars and 36 cents, he's similar to Nick. (Appears in the episode Attack of the Twonkies)
Cap'n Betty, an odd sailor who knows about a monster, which is actually Carl's mutated pet turtle, voiced by himself (appears in episode Monster Hunt, My Big Fat Spy Wedding, and numerous cameos, many of them well-hidden).
Chip, A teenage hologram of Skeet, used by Jimmy to fool his parents into thinking a camping trip is supervised. He is voiced by Rob Paulsen. (appears in episode A Beautiful Mine and makes various cameos throughout the show, such as in Best in Show.)
Chuck Lester, The short-lived hall monitor who moved away to Greece. He was voiced by Crystal Scales (appears in episode Hall Monster; Also is seen on Butch's team in the episode "The Retroville 9").
Coach Gruber, the coach of Lindbergh Elementary. He is voiced by Jim Belushi.
Colonel McSwane, the head of the Atomic Monkey Special Forces Squad. Saved Carl and Sheen from captivity in My Big Fat Spy Wedding.
Commander Baker, the Big Top Secret Organization commander. He is voiced by Michael Clarke Duncan (appears in episode Operation: Rescue Jet Fusion, My Big Fat Spy Wedding).
"Cool" Hugh, the cooler variation of Jimmy's father seen in the Father's Day episode. He was voiced by Mark DeCarlo.
Corky Shimatzu, a famous Japanese big-shot TV programmer, whose catch-phrase is "Super Crazy!" with no relation to the professional wrestler. He is voiced by Billy West.
Courtney Tyler, Britney, Libby and Cindy's friend; she is one of Jimmy's classmates. She usually appears in the background and is rarely mentioned in the show. She has black hair and wears a purple shirt.
Cousin Gomer, Jimmy's other cousin besides Cousin Eddie, he sounds like Gomer Pyle from The Andy Griffith Show and Gomer Pyle, U.S.M.C.. Seen in Clash of The Cousins.
"Crazy" Louie, mentioned in Stranded. Cindy would rather want Louie be with her on the island because he can open coconuts with his tooth (until the ending of the episode when she'd rather be with Jimmy Neutron).

D

Dr. Dark/The Pizza Monster, A story-telling hologram gone awry, and the hologram and pizza hybrid that appears when Jimmy's sleepover machine goes haywire, Both voiced by Corey Burton. (appears in episode Sleepless in Retroville)
Dean Kane, dean of Pomona School of Advanced Physics, or SAP (his name is a parody of actor Dean Cain or less likely Dean Kamen)
Doctor Sydney Orville Moist, A paranoid dance-crazy scientist that works under water making algae men and then became Jimmy's enemy. Collaborated with Professor Calamitous in The Jimmy Timmy Power Hour 2: When Nerds Collide briefly before being betrayed and ejected.

E

Emily,a redheaded bespectacled appears in the background often, in the episode Love Potion #976\j she told her boyfriend Oleander how to make a greeting card for her (although Oleander's supposed to surprise her) (Voiced by Debi Derryberry).
Elves, Santa and Nicole Clause's elves. All are voiced by Jeffrey Garcia. (appears in episode Holly Jolly Jimmy)
Elke Elkberg, Carl's hot pen pal from Sweden. Only seen in Carl Wheezer: Boy Genius.
Mr. Estevez, Sheen's elusive father, voiced by Carlos Alazraqui.
Eunice Willoughby, Principal Willoughby's sister. A picture of her appeared at the end of Hall Monitor, dressed as Albert Einstein. She was a hall monitor once.
Eustace Strytch, a rich, snobby kid seen in Billion Dollar Boy, King of Mars, The League of Villains, and The Jimmy Timmy Power Hour 3: The Jerkinators. He is the bitter rival of Jimmy, and has an extremely annoying laugh. Voiced by Rob Paulsen.
Ernest Abercrombie, the military general. Not as smart as he looks. And still han't turned in a homework assignment to Ms. Fowl after 28 years. Appeared in N-Men, and Substitute Creature.

F

Future Copbot, a robot from an alternate future with four arms that loves Grey Star music and works for Libby. He has the ability to clone himself. Voiced by Tom Kenny. (appears in episode The Tomorrow Boys)
Mr. Folfax, Libby's father, appears in the episode Make Room For Daddy-O. He's similar to Mr. Estevez.
Mrs. Folfax, Libby's mother, appeared in Journey to the Center of Carl. She is seen trying to cure Libby from Jimmy's sick patch by placing a wasp in a cup on her forehead. voiced by Crystal Scales.

G

General Ernest Abercrombie, a dull-witted military general who was a student in Ms. Fowl's class, voiced by Ernest Borgnine.
Giggles the Clown, the boring voiced clown (who ends up doing boring tricks if he runs out) seen in the Hypno Birthday To You and the Foul Bull episodes, voiced by Ben Stein. Also makes a cameo in "Sheen's Brain" in the costume shop's window.
Goddard- Jimmy's only successful invention shown throughout the shows as his loyal robot dog. He can fly him around, do tricks like an ordinary dog and never breaks down.
Granny Neutron, Hugh's mother and Jimmy's grandmother. Jimmy once turned her into a baby in Granny Baby, voiced by Phyllis Diller.
Grandma Taters, a sweet-seeming old lady who is actually a hostile alien. Tried to turn the citizens of Retroville into cheerful zombies. Featured in One of Us and The League of Villains, voiced by Edie McClurg.Makes a cameo appearance in Best In Show.
Grey Star, Libby's favorite band. They are college students in Jimmy Goes to College. They also have a cameo appearance in the episode The "Incredible Shrinking Town". They are seen in the background as Butch and Nick are picking for basketball team members at the beginning. The Future Cop-bot is a huge fan of theirs. (Appear in Attack of the Twonkies, The Tomorrow Boys, Jimmy Goes to College, and The Incredible Shrinking Town.)They are a possible reference to the punk rock band, "Green Day".
Germ a T4 phage bacteria that made an appearance in Journey to the Center of Carl and made a cameo in Win, Lose and Kaboom!

H

Hilgo, the big, fearsome maid that can only say one word---"Da" (Russian for yes) ---and was seen in Time Is Money she also made a guest appearance in Return of the Nanobots as a lunch lady who once made shoes for lunch, voiced by Jill Talley.
Humphrey, Cindy Vortex's dog seen in many episodes usually accompanying her.

I

Ike Wolvermein, One of Jimmy's classmates, he is one of the cool kids in Lindberg Elementary School. (Voiced by Crystal Scales)
Ignishka Stroganovski, Bolbi's sister. She looks very much like Bolbi, except she wears a dress and she has blonde hair with 2 long pigtails.
Invisible Sister, Libby's superhero form, her power is to turn invisible and project force fields, voiced by Crystal Scales. Her powers may be based on Violet from The Incredibles or The Invisible Woman in The Fantastic Four. (appears in The 'N' Men)

J

Japanese Announcer, an unseen character from Japan voiced by Michael Hagiwara. (appears in episode Retroville 9)
Jet Fusion, Jimmy, Carl, and Sheen's (2nd) favorite superhero. A parody of James Bond ("bond" and "fusion" mean the same thing). He is voiced by Christian Slater. (appears in episode Operation: Rescue Jet Fusion, My Big Fat Spy Wedding)
Jimmy's dancing girls, two attractive women used in Jimmy's Presidential campaign. One is voiced by Terry Wood and the other one is voiced by Amber Wood. (appear in episode Jimmy For President)
Jimmy Clones: Happy, Gloomy, Funny, Cool, Romantic, and Evil, Clones of Jimmy. All voiced by Debi Derryberry except for the evil clone who is voiced by Rob Paulsen. In Send In The Clones, Jimmy made these clones to do his chores while he harvested moon rocks. Jimmy's clones caused trouble, and he had to stop them, but the Evil Jimmy got away. In The Trouble with Clones, Evil Jimmy came back, and started hypnotizing people when Jimmy tried to turn him good and hired him to do the chores. Evil Jimmy then made an evil clone of the Earth, causing the real Earth to disappear. The original Jimmy went to that Earth and had to reverse the effects. In the end, the real Earth is saved, and the cloned Earth, along with Evil Jimmy, were sucked into the Dark Matter Dimension. All of the clones are possibly deceased
Ms. Jingle Bells (Megan Cavanagh; appears in episode Operation: Rescue Jet Fusion) A girl rescued by Jet. A parody of various Bond girls.
Junkman (Charlie Adler; appears in episode The Junkman Cometh, The League of Villains and makes a cameo in The Best In The Show as a contestant, and Win, Lose and Kaboom), a filthy creature from another planet. Deals in fixing up and selling refuse products throughout the galaxy- "you trash it, I cash it!"
Jimmy Negatron (Debi Derryberry; only appears in the game Jimmy Neutron vs. Jimmy Negatron) An evil version of Jimmy from another dimension, kind of like Evil Jimmy but he looks and sounds more like the original Jimmy, only he has a goatee.

K

King Goobot, the Yolkian King (in the original film by Patrick Stewart of Star Trek: The Next Generation fame, in the series by S. Scott Bullock); appears in The Eggpire Strikes Back and League of Villains

L

Lance (Billy West; appears in episode The Retroville 9)
Lars Svenson (Billy West; appears in episode The Science Fair Affair) He is from Sweden
Libby's little brother The legs in Libby and Mr. Folfax's magic trick. (Crystal Scales; appears in episode Make Room for Daddy-O)
Living Lima bean Appears in I dream of Jimmy and made a cameo in Win Lose and Kaboomdeceased
Lou (Billy West; appears in episode Holly Jolly Jimmy)
Lucky Joe, has an eyepatch (Billy West; appears in episode When Pants Attack)

M

Maggie (Crystal Scales; appears in episode Birth of a Salesman)
Masseuses (Megan Cavanagh; appear in episode MaternoTron Knows Best)
MaternoTron, Jimmy temporary replacement robot Mom. (Megan Cavanagh; appears in episode MaternoTron Knows Best)
Max, (Tom Kenny; appears in episode Maximum Hugh)
Mayor of Retroville (Jim Cummings, later Tom Kenny; has a resemblance to Walt Disney and Clark Gable and later wears a top hat and a monocle; seldom appears)
Meldar Prime, evil host of gameshow Intergalactic Showdown. Appears in Win, Lose and Kaboom Voiced by Tim Allen.
Mayor Quadar (Mark DeCarlo; appears in episode "Normal Boy")
Mombot (Grey Delisle; Brobot's Mom, appears in episode Brobot and The Junkman Cometh)
Monks of Shangri-Llama, (appear in episodes Operation: Rescue Jet Fusion and Crouching Jimmy, Hidden Sheen)
Mr. Moodini (Tom Kenny; appears in episode Maximum Hugh)
Mummies (appear in episode Beach Party Mummy)
Morgan Freeman, Sheen wished that he would be Morgan Freeman's best friend, but then Sheen is annoyed by him. (Appears in the episode Jimmy Timmy Power Hour 2: When Nerds Collide) (Voiced by Kevin Michael Richardson)

N

Nanobots (Daran Norris and Tom Kenny; appear in episode Safety First, Return of the Nanobots, and Fundemonium.) Attempt to "please" their creator, Jimmy. They don't usually get along. The Nanobots saucer module is actually an allusion to the saucer module in the movie "Batteries Not Included."
Nathan Decarlo (Jeffrey Garcia; seldom appears)
Nissa (Debi Derryberry; seldom appears) A "one toothy girl" that taunted Jimmy once.

O

Octopus Man, a movie monster ("he has 8 arms!") (Mark DeCarlo; appears in episode Nightmare in Retroville as a monster in a movie that Hugh was watching.)
Officer Tubbs (Frank Welker; appears in episode Jimmy On Ice, Professor Calamitous, I Presume,Holly Jolly Jimmy, and Who Framed Jimmy Neutron)
Old Carl (Rob Paulsen; appears in episode Granny Baby, and Grumpy Young Men)
Old Lady Nussbaum (Megan Cavanagh; appears in episode Normal Boy)
Oleander, an odd geek bullied by Butch, and once owed Sheen 53 cents (Rob Paulsen; seldom appears)
Ooblar, Yolkian sidekick of King Goobot (in the original film by Martin Short, in the series by Paul Greenberg);
Ozzie (Crystal Scales; appears in episode The Retroville 9)

P

Phantom, (appears in episode Phantom of Retroland)
Popbot (Jim Cummings; appears in episode Brobot and The Junkman Cometh), Brobot's father robot.
Poultra, original chicken goddess of Yolkian race (only appears in original movie and in The Eggpire Strikes Back)
Principal William S. Willoughby, The flamboyant, Broadway-loving Principal at Lindbergh Elementary School (Rob Paulsen; seldom appears)
Princess Guan Qi "Peggy" Tsu (Ming-Na; appears in episode The Great Egg Heist. She is really Professor Calamitous in disguise.) Also appears in the background of "My Big Fat Spy Wedding".
Professor Crank (Dan Castellaneta; appears in episode Operation: Rescue Jet Fusion)
Professor Finbarr Calamitous, (Tim Curry; appears in episodes Professor Calamitous, I Presume, The Great Egg Heist, Operation: Rescue Jet Fusion, The League of Villains, Lights! Camera! Danger!, My Big Fat Spy Wedding, and The Jimmy Timmy Power Hour 2: When Nerds Collide). Ms. Fowl's former student, despite his age. Finbarr Calamitous was once a brilliant boy who could never finish anything, not even a sentence. He later overcomes this, and Finbarr Calamitous is heard completing sentences as seen in Operation: Rescue Jet Fusion, The Great Egg Heist, and The Jimmy Timmy Power Hour II. Out of all of Jimmy's adversaries, he has made the most appearances in the series. He has also been the main enemy in Nicktoons Unite! and Nicktoons: Attack of the Toybots where he faced more of the Nicktoon heroes including Danny Phantom and SpongeBob SquarePants.

Q

Queen Howsaboutislapya, a fictional Egyptian queen said to be an ancestor of Libby, her name is a pun on "hows about I slap ya"?
Quentin Smithee, a movie director who is an obvious parody of Quentin Tarantino. His name is also a reference to Alan Smithee, a pseudonym used by directors who wish to distance themselves from a film. He is later revealed to be Professor Calamitous in disguise. Even though the character was devised by Calamitous, a person who looks just like him can be seen in the church in the episode My Big Fat Spy Wedding

R

Rayburn, the holographic butler (Corey Burton; appears in episode Aaughh!! Wilderness!!) Rayburn also appears in "Win Lose And Kaboom!" as a real person and "The Jimmy-Timmy Power Hour III" as Cindy's family butler and in "Gumpy Young man" as a cameo (not hologram) when Carl takes his picture in front of the giant space rock.the hologram version of him is deceased
Robo-Fiend, Lactose-intolerant enemy of Ultralord (Rob Paulsen; appears in episode Ultra Sheen, mentioned often by Sheen)
Roxy, the Junkman's alien dog that looks like a French Poodle and is Goddard's crush. Appears in episodes, The Junkman Cometh and League of Villains

S

Sagebrush Sally (Grey Delisle ; appears in episode Foul Bull)
Sam Melnick, owns the Candy Bar (Billy West). Sam ends every sentence by saying "Yeah!"
Santa Claus (Mel Brooks; appears in Holly Jolly Jimmy)
Sasha Vortex (Cindy's mother who doesn't look much like her daughter at all)
Susie Vortex, Cindy's aunt, award-winning athlete (Megan Cavanagh; appears in episode Maximum Hugh). Although her name suggests that she is Cindy's paternal aunt she actually resembles Cindy's mother.
Seymour Flimelflarb The "Official Smart Guy on Campus" at Pomona Tech. He is in the episode Jimmy Goes To College.
Sheezicks (Mark DeCarlo; appears in episode Maximum Hugh)
Shirley a.k.a. the villain who's not named Shirley, villain created by Jimmy Neutron and Timmy Turner {only appears in episode Jimmy Timmy Power Hour 3}
Skeet Calls everyone "dude" and is the employee of the month at the McSpanky's fast food restaurant. (Rob Paulsen; appears in episode Men At Work) Skeet also is holographed in "A Beautiful Mine" as Chip the holographic bus driver. In "Best in the Show", he can be seen at the pet show with a pet monkey.
Snappy, Carl's mutated turtle (appears in episode Monster Hunt)
Special Girl, Cindy’s super hero form, strength, flying, and super vision
Swimmy, Carl's undead goldfish (appears in episode Beach Party Mummy)
Spamdini, The great,a magician that lost his hand and got it back, he hates tuna, he loves pastrami, he's a parody of the famous magician Harry Houdini. (Voiced by Corey Burton) (Appears in the episode Vanishing Act).

T

Tee (voiced by Kevin Michael Richardson) is one of the three alien claim-jumpers. He appears in episodes A Beautiful Mine, Men at Work, The Incredible Shrinking Town and The League of Villains. He is known to turn good in The League of Villains. He enjoys hugging, and dreams of opening a dress shop. Tee also hates it when people call him stupid, and says "Foo!" a lot. His name, action and personality are all a knock-off of Mr. T.
Terry Finster (Candi Milo; appears in episode Safety First and can be seen in the oufield in Retroville 9.)
Thomas Edison (Rob Paulsen; appears in episode The Big Pinch)
The Three Amigops There are two groups of the three amigops. The "real" version is the group of friends that includes John Valentic, Bryce Sedio, and Brenton Krivos. The three amigops that came along later is found on a Jimmy Neutron episode where Jimmy and Cindy Vortex have there brains switched. Carl Wheezer, friend to Jimmy, makes nametags for him, Jimmy, and Shean Estavez. But, Carl spells amigos wrong and it turns out amigops. He refers to this right before they get in the hover car, and right before Cindy and Jimmy put there brain knowledge in a bowl to be divided to each of them.
Tina Sue (Carolyn Lawrence; appears in episode Operation: Rescue Jet Fusion)
Travoltron (Jeff Bennett ; the second of three alien claim-jumpers, appears in episode A Beautiful Mine, Men at Work, The Incredible Shrinking Town and The League of Villains) His name was probably made by the fact that he sounds like John Travolta. In first appearance he was named Barbarino.
Tremendous Jackson, baseball star and UltraLord expert (Kevin Michael Richardson; appears in episode The Retroville 9)
Twonkie, a small puff ball that turns into a larger monster every time it hears music. They get put to sleep by Sheen's 'terrible singing'. If twonkies that have already heard music and turned into orange monsters go into a small space, they will turn into a huge, invincible monster that can only be subdued by Sheen's bad singing. The pink twonkie makes many cameo appearances in many of the episodes that have aired after the Attack of the Twonkies.

U

Ultralord, a superhero that Sheen is really obsessed with. He has his own show (which is also named after him). His enemy is Robo-Fiend (voiced by Jim Cummings).

V

Vibrating Lad, Sheen's superhero form. His power allows him to vibrate his molecules at fast speeds, allowing him to run faster (in episode The 'N' Men).
VOX (Megan Cavanagh); Jimmy's computer, rarely heard in later seasons.

W

Wendell (voiced by Frank Welker; appears in episode Make Room for Daddy-O)
Mr. and Mrs. Wheezer, share many of Carl's allergies and hypochondria (Rob Paulsen).
Willy Loman 3000, the ultimate sales robot (Tom Kenny; appears in episode Birth of a Salesman, named after Willy Loman of Death of a Salesman).
Winifred Fowl, Jimmy's teacher (the only one ever seen on the show). She teaches multiple subjects including math, history, and English. The inimitable Ms. Fowl's name plays upon her birdlike nature. Though old, she lacks any of the graces that age can and generally does bestow upon those who have lived a productive and rewarding life. She brings a surprising level of fresh humor to a cliched part, the part all adults play in children's cartoons --the clueless adult. This freshness can best be observed in her alphabet song. "A is the letter that we all should know. Without it we can't spell ant. B is the letter that we all love so. Without it, there'd be no botulism."
Mr. Wuggles, Carl's hamster (Frank Welker; appears in episode My Son, the Hamster).Responds to when Carl says "Wuggle Wuggle Wuggle".

Y

Yentil Marvelstein (Debi Derryberry; appears in episode Journey to the Center of Carl) A sick child that joins Jimmy's classroom.
Yoo-Yee (James Sie; only appears in episode Crouching Jimmy, Hidden Sheen)
Yuri, Bolbi's pet goat who's skilled at music; appears in Best in the Show.

Z

Zix, (Maurice LaMarche; leader of Tee and Travoltron, appears in episode A Beautiful Mine, Men at Work, The Incredible Shrinking Town and The League of Villains) He appears to be based on comedian Jon Lovitz.

Running gags

A running gag in the series is that most of the named characters have flaws. Jimmy is a genius, Sheen is hyperactive, Carl is allergic to practically everything and a hypochondriac, Cindy is in love with Jimmy but won't admit it, Libby is obsessed with music, Mrs. Fowl is like a bird, Hugh is obsessed with ducks and pies, Judy is a neat freak, Butch is a bully, and so on.

Another running gag is that whenever one of Jimmy's inventions goes haywire and dangerous, Carl or Sheen or both will say that their life has flashed before their eyes, then briefly pause their panic to bring up a ridiculously-sounding or embarrassing moment from their past, then return to their state of panic. Sometimes, but not often, the other will confirm the moment.

At some point in almost every episode, Carl is hurt and moans, "ow, my scapula." Despite his injury often being of a different body part.