The show hasn’t been on the air in 15 years, but stillThe Adventures of Jimmy Neutron: Boy Geniusgoes down as a memorable kids' animation that featured some of themost iconic 2000s cartoon charactersever. Now, the mention of the show takes Millennials back to their time as science fiction cartoon-loving youngins, proving thatJimmy Neutronis akids show adults can enjoyas well. The swirly-haired mastermind was first introduced in the 2001 movieJimmy Neutron: Boy Genius. The theatrical film followed Jimmy and his friends who, after a clan of egg-shaped aliens kidnapped their parents, temporarily and gladly lived an unchaperoned life until they came to the very true realization that they indeed needed adults to care for them. Its popularity spun off into a half-hour series that aired on Nickelodeon from 2002 to 2006.

With computer animation,Jimmy Neutron, at the time, was one of a kind for its three dimensional-looking style. However, viewers were thrice able to see Jimmy and his friends as 2D drawings in theJimmy Timmy Power Hourspecials which merged the series with another Nickelodeon classic,The Fairly Oddparents. WhileJimmyNeutronrevolved mainly around the title character, he had friends, enemies and a robot dog compiling the ensemble we still know and love. Years later, here’s how the characters fromJimmy Neutronrank.

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Cindy is Jimmy’s frenemy, beginning the show as his rival but eventually warming up to him. Though the blonde-haired tai chi master is spoiled and bossy, she can also be smart (almost as smart as Jimmy!), loving, and caring. Cindy was once the most intelligent kid around until she met the lead character, which ultimately started their feud. Her jealousy turned into torment, and she constantly gave Jimmy a hard time whenever he made a mistake. She might have begun as Jimmy’s nemesis, but as the show progressed, their hatred took a turn and the two developed feelings for one another and eventually began “dating.”

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Libby is Cindy’s best friend. Like her blonde bestie, resentment towards Jimmy and his friends eventually formed into friendship, or friendship forsomeas Libby would someday go off to become Sheen’s girlfriend. Libby began the series with a blue dress and straight hair tied into a bun, but after discovering she was Egyptian royalty, her design changed to a pink top, jeans, and most noticeably, a completely new hairdo. Like her Egyptian ancestor, whom Libby favored in looks, she now wore short, thick box braids. Her biggest interest is hip hop and R&B music, and she’ll go as far as to faint if she’s deprived of it.

From the UltraLord T-shirt and the UltraLord action figures to the very important question, “What would UltraLord do?,” it’s clear Sheen has got an obsession with the purple superhero, to the point that it’s nearly impossible to know the energetic 13-year-old without relating him to his favorite hero. Sheen is one of Jimmy’s best friends, completely opposite of Carl, being a hyperactive, enthusiastic space cadet — emphasis on “space,” with Sheen gaining his own show calledPlanet Sheenin 2010. In his spinoff, after stealing Jimmy’s rocket ship, he gets blasted off to another planet with other characters mimicking those ofJimmy Neutron.

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The main protagonist of the show, of course, James Isaac Neutron would be riddled with likable traits, and qualities – like his name being a reference to Sir Isaac Newton – that show he’s got a big brain. He even walks around in a T-shirt with an atom on it. At only 10 years old, Jimmy can easily use his scientific knowledge to solve problems and invent devices that can do almost anything. Viewers have witnessed Jimmy’s coming-up with events, as he thinks super hard chanting, “Gotta think…” and shouting “Brain blast!” once he knows what to do. As previously mentioned, Jimmy has a love-hate relationship with Cindy, with Jimmy finally kissing her in the final season.

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Robot. Dog. And that’s all that needs to be said to prove just how cool Goddard is. Named after Robert H. Goddard, an American engineer, the Neutron family pet is a mechanical canine that Jimmy invented all on his own. Jimmy’s genius abilities allowed him to rig Goddard up with cool gadgets and abilities like flying, turning into a bicycle and playing dead — which, to him, means self-destructing. They say a dog is a man’s best friend, and for Jimmy and Goddard this is undeniably true. Goddard is a loyal pet to Jimmy and is always by his side when needed.

Carl is the epitome of a cliché nerd character. With allergies, cowardice, and especially his circle-shaped eyeglasses, it’s clear that upon seeing him, you know Carl is indeed a geek. Still, the round little boy is sweet as a peach and has a soft spot for llamas. Basically, llamas are to Carl as UltraLord is to Sheen. He’s even part of a fan club called The Llama Love Society and frequently plays a video game named Llamapalooza. Carl also has a crush on Jimmy’s mother, though it’s evident that she does not reciprocate these feelings. Carl is, however, to put it simply, incredibly pure with a sweet voice that only further proves his innocence.

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