Litten is a quadruped, feline Pokémon covered with primarily black fur. It has a short muzzle with a tiny, black nose, red eyes with yellow sclera, and short, pointed ears with pale gray insides. There are two red stripes around each of its legs and two horizontal stripes with a vertical stripe across them on its forehead. The lower part of Litten's face is also red, and there is a large tuft of fur on each cheek. A tuft of fur sits at the end of its long tail. When it arches its back, three pointed tufts of fur with red tips appear along its spine.
Litten is a solitary Pokémon that does not typically display its emotions. While grooming, it collects fur inside its stomach. By setting the stored fur alight, it can spit fireballs that change based on how it coughs. Litten's fur produces flammable oils, and when it begins shedding, it burns all its fur in a blaze.