When first appearing in a major role, he is a boy that Veronica goes out on a date with. Though initially appearing affable and considerate, it later comes to light that he practices "slut-shaming", and he and his fellows have now made Veronica the latest victim, spreading false rumors about her conduct with Chuck and humiliating her for their own sadistic pleasure. Enraged, Veronica confronts Chuck and demands that he recant his lies, but he arrogantly refuses and mocks her instead.
Veronica and Betty subsequently discover other victims of the slut-shaming ring, locate the "book of conquest" that Chuck and his fellows use to record their activities, and then Veronica and Betty dope up Chuck, chain him to a jacuzzi, and torture him into confessing to the truth of his date with Veronica (which is, of course, more harmless than the lies he had been spreading). After the truth comes out, a disgraced Chuck is suspended.
He later returns, again putting on a charming facade and pretending to be repentant regarding his earlier actions. In fact, he is now vengeful, working with Cheryl Blossom to crash Jughead's birthday party and needle Betty, Veronica, and Archie with various remarks that are personal to each of them (Betty's issues with her sister, Veronica's vindictive acts against him, Archie's affair with his teacher, etc.) Eventually, Jughead gets into a fist-fight with Chuck that his father breaks up before ordering Chuck to leave.
Chuck appears yet again in the second season, now legitimately repentant and eager to make up for his previous bad behavior. He attempts to woo Josie, who initially rebuffs him out of disgust before being gradually won over by his newfound earnestness. Unfortunately for Chuck, he is later framed for harassing her and threatening her, and punished yet again, ironically this time being the one instance where he wasn't guilty.
In the comics, Chuck Clayton was a friendly and easygoing character, as well as a longtime friend of Archie and the gang.