Chester is blond and wears an olive green coat over a black shirt and jeans. The long end of his hair switches to the opposite side of the screen depending on how he is standing. He also has braces, although in some episodes it's a retainer. When Chester became a teenager, he no longer has his braces.
Chester is a fan of Crimson Chin comic books. Like Timmy and the rest his friends, Chester is considered one of the "unpopular kids", although even then he is usually picked by the other kids who want him on their team over Timmy. He is usually bullied by Tad, Chad, and Francis.
Chester does not seem to like girls much, stating that they "give him hives". However, on Timmy's trip around the world, Missy told him how to be immune to hives, and since then, Chester doesn't mind being around girls.
Chester has been shown to have an appetite similar to that of the Yugopotamians. He is often seen eating garbage from the can. However, Chester also has standards, as he doesn't eat manure.