|Relationship||Judy Neutron (one-sided), Elke Elkberg ("Carl Wheezer, Boy Genius")|
|Family|| Ebenezer Wheezer (dad)|
Martha Wheezer (mom)
|Friends||Jimmy Neutron, Goddard, Sheen Estevez, Libby Folfax, Cindy Vortex, Nick Dean|
|Likes||Llamas, Judy Neutron, messing with Hugh Neutron and food.|
|Dislikes||Germs, lima beans, scary stories, spiders and Hugh Neutron|
"Baby-Faced" Carlton Ulysses "Carl" Wheezer is one of Jimmy's best friends. According to canon, he is currently 12 years old.
Carl likes to eat, and this caused him to be overweight. When his parents expanded their cable line-up, Carl found himself focusing on a channel devoted to llamas and a show about a superhero called Llama Boy the Super Hero. He has adored llamas ever since, going so far as to join a fan club, the Llama Love Society (Which he likely created as he is shown to be the first member). He once turned into a llama. He is allergic to almost everything. Carl is also the one who unknowingly gives Jimmy his brilliant ideas.
It is revealed in "The Incredible Shrinking Town" that he took ventriloquist lessons, and that he can virtually imitate and sound just like everyone. It is also a hinted that he has some sort of dislike for Sheen, even though he's one of his best friends. Carl enjoys playing a video game called Llamapalooza. It is also revealed in two episodes that he actually is envious of Jimmy and wants his life.
It was stated by himself that he as always wanted to touch a Llama in the movie.
- In Carl Wheezer, Boy Genius, he was the main antagonist; he betrays Jimmy and starts verbally abusing him, even after the many times Jimmy saves his life. When Jimmy saves Carl for the third time, Carl blames Jimmy for everything (even though he was highly responsible) and pins all his insecurities on Jimmy. Despite the fact he was a jerk throughout the whole episode, Elke still falls for him and Carl doesn't even apologize to Jimmy.
- In I Dream of Jimmy, he secretly dreams of Jimmy being his servant and puts him through some torture. It is also revealed he wants Jimmy's life.
Carl has peach skin and many freckles. He has a pair of small black eyes and red hair. He often wears an orange-and-red striped shirt, a pair of green pants (shown with suspenders in the movie), a pair of brown loafers, and glasses. Carl has also been left in his underwear on numerous occasions. Carl is shown to wear a nice pair of tighty whities.
- "Ok, I'll have one more and then that'll be it." - Jimmy Neutron: Boy Genius
- "Um, yes, are you going to finish that croissant?" - Lights! Camera! Danger!
- "Time to take out the trash!" - Sleepless in Retroville, Attack of the Twonkies
- "OUCH! Sheen, that hurt!" -Broadcast Blues
- "Ow, my scapula!" (numerous episodes)
- "Llama, llama, llama!" -Jimmy Neutron: Boy Genius
- "I don't know, Jimmy..." (Usually when testing one of Jimmy's inventions)
- "Saying goodbye to your kids is always painful, Jimmy." - Who's Your Mommy
- "It's a good thing my underwear was clean." -King of Mars
- "Guys, can I have my pants back?" -King of Mars
- "But why did you wink? Why'd you gimme a dollar?! My brain hurts!!!" -Jimmy for President
- "Thanks. I saw that in a soap opera once..." -Raise the Oozy Scab
- "Who's eating whom??" -Stranded
- "Flying metal chicken..." -The Eggpire Strikes Back
- "I want my mommy!!!! ...And some fudge." -Hall Monster
- "So?? Pinching still hurts!" -Normal Boy
- "Thanks, guys! I thought I was gonna be snake food!" -Beach Party Mummy
- "Aw, c'mon, guys. Eighth place isn't so bad..." -Battle of the Band
- "Jimmy, why is it so unseasonably humid?" -Sorry, Wrong Era
Carl has appeared in most of the episodes of The Adventures of Jimmy Neutron: Boy Genius along with Jimmy and Sheen. His first appearance was in Runaway Rocketboy!. His last appearance was in the series finale "Jimmy Timmy Power-Hour 3: The Jerkinators".He also appeared later in the spin-off series; Planet Sheen , during Sheen's flashback of him and Carl in the episode Is This Cute? when comparing similarities between him and Doppy. He also appeared in the ride Jimmy Neutron's Nicktoon Blast. He and Doppy has the same voice and resemblance.
- Carl Wheezer is similar to Milhouse van Houten from The Simpsons.
- He has a crush on Judy.
- Carl makes a cameo in a flashback in the Planet Sheen episode, Is This Cute?.
- Carl 'hosted' Rob Paulsen's "Talkin' Toons Podcast" on July 6th, 2012. In it, he reveals many hidden details including the fact that Doppy was just him in a costume, Sheen is currently in a juvenile detention center (back on Earth after returning from Zeenu), and at one point he had a crush on Cindy Vortex. However, this is most likely not canon.
- It was revealed in The Incredible Shrinking Town, that Carl took ventriloquist lessons. He was going to sound like Cindy, but never got the chance. However, in the episode he did sound like Ms. Vortex (Cindy's mom) and Zix.
- In Journey to the Center of Carl, It reveals that Carl eats his toys because it tastes fruity and chewy.