Nick has styled black hair and tan skin. He wears a blue jacket with a white shirt under it in the movie and first season, though changes to a black leather jacket in the second half of the second season and for the rest of the series. He does still have his old outfit in clipart, storybooks, video games and merchandise, however. He wears a pair of hi-top sneakers and he wears dark blue jeans in each of his appearances. He breaks his leg from time to time due to reckless stunts, usually on his skateboard.
Nick is 13 years old, the second oldest of Jimmy's best friends, having to repeat fifth grade due to tardiness, but is also very street. He is one of the towns' wealthiest children, living in a 92-room mansion, with a bowling alley, maids' quarters, a screening room and a soda parlor. Nick enjoys giving advice to Jimmy and serves as a big brother towards him. He can sing operatic German, which he only does secretly, as he thinks it is uncool. He can also style his hair without using his hands and is very vain about his hair, often flipping it around. He breaks his leg from time to time due to reckless stunts, usually on his skateboard, and became known for his high-pitched scream that he lets out when this happens. In some cases, Nick is shown to be a bit of a mama's boy and he also has a soft spot for Brittany, which he doesn't show in public because it would ruin his reputation. Nick and Sheen argue a lot because Nick finds Sheen annoying and immature, and the fact that Nick has a short temper.
- "Dude, you're not a dude!!" -See Jimmy Run
- "Dude, my 'do is RUINED!!!" -Attack of the Twonkies
- "I'm gonna style my hair without using my hands. Can I get a drumroll, please?" -Broadcast Blues
- "Whatever, Neutron. But remember that there's only one opening night, and anybody who matters is gonna be there!" (skates into the alley) -Jimmy Neutron: Boy Genius
- "Augh, what's that smell?!" -Phantom of Retroland
- "Whoa! Check it out! Neutron has the moves!!" - Send in the Clones
- "Let me respond to that in the following way..." -Crime Sheen Investigation
- "I officially declare this party OVER... Out of my way, Shine!!" -Party at Neutron's
- "Augh!! I broke my leg!!" -My Big Fat Spy Wedding, Out, Darn Spotlight
- "Hey, Neutron. What did the Yokians give you?" -The Eggpire Strikes Back
- (mutters helplessly) "No more leeches, Mama! No more leeches, Mama! No more leeches, Mama!" -Journey to the Center of Carl
- "What have you done, Neutron?! I'm not beautiful anymore! Oh, wait... (holds up a mirror) Yeah, I am." (HONK!!!) -The Trouble with Clones
- "Why does this keep happening to me?!" -The League Of Villains
- "You know, these are as cool as... me!" Krunch Time
- Jimmy always ends up in trouble when he takes Nick's advice.
- While Nick had a fairly large role in the movie and season one, he was reduced to a secondary character for the rest of the series. He was going to rejoin the main cast in season four, however.
- Jimmy and Nick are the only male characters to be voiced by a female. Jimmy is voiced by Debi Derryberry and Nick is voiced by Candi Milo.
- In the movie, he was always holding a purple lollipop, but this was later removed in the show, with the exception being The Eggpire Strikes Back.
- He probably wears briefs, as seen in "The Trouble with Clones," where his evil clone was given a wedgie.
- Aside from Butch, Nick is the only character in the franchise who never refers to Jimmy by his first name, as Nick only refers to him as "Neutron", "Nerd Bomb" or "Boy Wonder". Although he does use Jimmy's first name in a few storybooks and in Make Room for Daddy-O.
- In the film, when the children reunite with their parents, Nick is shown with just a mother. This makes Nick the only one of Jimmy's best friends not to have a father. He is also one of the two characters we know who has a single parent. The other one is Sheen.
- Nick's last name is a reference to James Dean who is best known for playing similar "bad boy" roles.
- Many of the times he has broken his leg has been because of repeated tries to jump a fire hydrant while skateboarding.
- Cindy had a crush on Nick in the movie and early episodes and would often try to get his attention, but Jimmy kept ruining her chances with him due to his endless pranks. Her chances were ruined once and for all in Trading Faces when Jimmy made Cindy look like a fool in front of Nick. Nick and Cindy do remain friends, however.
- Originally, Nick was going to be black and more of a basketball jock, but he was changed to Brazilian and more of a bad boy.
- In the movie, his voice was more scratchy and high pitched, but in the show, his voice is a bit more deep and clear.
Main Characters: Jimmy Neutron | Carl Wheezer | Goddard | Sheen Estevez | Cindy Vortex | Libby Folfax | Nick Dean | Goddard | Hugh Neutron | Judy Neutron