Chimchar is a bipedal Pokémon resembling a chimpanzee. Its fur is primarily a shade of orange, although its face, outer ears, underbelly, hands, and feet are light yellow. Its ears are large in comparison to its head, and has red insides. It also has red markings around its eyes, as well as two pointed teeth in its upper jaw, a swirl-like symbol on its chest, and five fingers on its hands with three toes on its feet. It has a swirly crest of hair on its head. Its rear has a small, round, red patch that is usually obscured by flames produced by burning gas in its stomach. These flames cannot be put out by rain, although they go out when Chimchar goes to sleep, and burn weakly when it feels ill. In the past, this flame on its rear has caused people to mistake it for an apparition, dubbed the "Lantern-Tail". Chimchar is very agile, being able to climb the rocky ledges of tall mountains where it lives.
When Paul first appeared, he commanded a Chimchar in When Pokémon Worlds Collide!. In Glory Blaze, Paul released him before Ash Ketchum caught him in Smells Like Team Spirit. He evolved into a Monferno in Evolving Strategies! and later into an Infernape in Fighting Ire with Fire!.
A Chimchar appeared in Pokémon Evolutions under the ownership of Lucas. Lucas was shown choosing it as his first partner Pokémon when attacked by a wild Starly at Lake Verity. It later evolved into a Monferno and Infernape.