Eric Theodore Cartman, wears a light blue and yellow toque, a red jacket, yellow gloves, and brown pants. He has light brown hair, which has been regularly seen since late in Season 5 (his hair magically turns black whenever he wears his Adolf Hitler outfit). He has a double chin, and is often made fun of because of his obvious weight problem.

According to creators Trey Parker and Matt Stone, when they were creating South Park, they were upset that "nowadays, it would be impossible to put a character like Archie Bunker on TV." But they thought that if he was an animated eight-year-old boy, it might just be allowed. Thus, Cartman was born.

Cartman's personality has changed significantly over the series. While always being self-centered and bigoted, it seems that in the first two seasons of the show he was portrayed as a juvenile, stupid and immature bully with a much raspier voice. It seems that since then he has matured a lot more, with a more aggressive personality and a smoother, slightly deeper voice. His manipulative skills when it comes to getting other people to do what he wants have improved tremendously, along with his overall intelligence; traits particularly espoused in the episode Scott Tenorman Must Die. He is also much more well-informed and far less naïve on political and social aspects of the world, all things that the earlier Cartman would never be aware of.