|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|
|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.
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 the his two best friends. Carl enjoys playing a video game called Llamapalooza.
It was stated by himself that he as always wanted to touch a Llama in the Jimmy Neutron: Boy Genius Movie.
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 movie
- "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! That hurt!"
- "Ow, my scapula!"
- "Llama, llama, llama!"
- "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?'"
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 Mrs. Neutron.
- 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.