Upchuck's creepiness and attraction to any female apparently runs in the family; his father wants a new swimsuit for his secretary, and his attractive cousins make the same growling noise he does. He is possibly the only male character who expresses any physical attraction to Daria, despite her consistent insults.
In the finale, Andrea finally relents and agrees to his advances, which pleasantly shocks him.
Charles "Upchuck" Ruttheimer III was a student at Lawndale High, in Daria's class. In Malled, there is the implication that his father is rich; Diaries has his father as a businessman with "associates" who spent time overseas, confirming his wealth. Upchuck borrows his dad's credit card in Malled but manages to piss him off in "Diaries" by recording comedy answering messages on the house phone. He appears to be among the least-popular students at Lawndale High, at least as far as the females were concerned.
Perpetually-undeterred, Upchuck would make a sexual comment almost every time he appeared on-screen in the company of females, and would frequently deliver his catchphrase "Grrr...feisty!" in response to an insult or rejection thrown his way by women.
In Too Cute however, it is revealed that when push comes to shove, actually chickens out, being mortified by the sheer concept behind the breast enhancers Daria got from Dr. Shar. In "The Lab Brat," it's revealed out he spies on couples making out and takes photos of them. His father is Charles Ruttheimer the Second, who seems to own his own business. He also has two cousins, Brad and Brett, who are handsome, funny men who can attract girls—yet are shown to be on close terms with Upchuck (who they call "Chuck") and share his catchphrase.
Daria has a pretty casual relationship with Chuck. She gets annoyed with him, & he flirts with her incorrigibly, she doesn't seem to hate him. She allows him to take her on a tour of Brittany Taylor's house, & will engage in small talk with him. She and Jane Lane both can tolerate him, but they get annoyed with his constant advances & continually reject him. There is never any romantic tension between either of them, despite Chuck's continual propositions.
The only time Charles was ever successful at "picking up" a girl was in the Daria movie finale, Is It College Yet? In the final scene of the movie, he tried one of his suave pick-up lines on fellow student Andrea, and she nonchalantly accepted. He seemed very surprised but took advantage of the opportunity right away. This was unusual on Andrea's part, considering her comment to him in Fair Enough: "Don't touch me, you Howdy-Doody-looking creep." This seems to make Chuck very happy, and the two are assumed to end up blissfully dating.
Stacy helps Chuck pull off an amazing disappearing act at Lawndale High. This is the only occasion in the television series where a girl willingly worked with Upchuck. The status of their relationship is pretty relaxed, though some believe there was a romantic aspect.
Other than the ladies, another of Upchuck's interests is magic. He'd perform simple tricks for shoppers at Lawndale Mall, and once pulled off an amazing disappearing act at Lawndale High, with the help of Stacy Rowe. Upchuck appears to have an aptitude towards broadcasting, as he is the PA announcer for the Lawndale Lions football team and the DJ at the school dance in Daria Dance Party.
He maintains his own website (Ultrasuave Universe, at www.ultrasuave.com) with an archive of pick-up lines, jokes, pictures of himself, snippets of songs, and a "Gallery of Feisty Babes". The links and Feisty Woman section show he's a fan of the Aeon Flux cartoon; of comedians Jerry Lewis, the Three Stooges, and Monty Python; and superhero comic books, specifically Captain Muscle. Upchuck has a huge collection of pornographic magazines - Brittany refers with disgust to having to file them in "The Lab Brat".
Chuck is working on a Shemp Howard Search Engine. In 2000, MTV's website revealed Upchuck now owned now ran The Hubba Hubba Hub after Ultrasuave was "destroyed by a virus slyly concealed within the now-infamous SEXXXY SCULLY SNAPS attachment." His 'future ego' in IICY? shows him as a fashion designer, surrounded by models.
- He drives a Volvo sedan.
- In the Latin American dubbing, he was voiced by Carlos Iñigo.