Simisear is a simian Pokémon that is primarily red. Its ears are broad with orange insides, and it has oval eyes and a small black nose. It has a swirled, flame-like tuft on its head with a smaller tuft on either side of it. Simisear has white shoulder ruffs; and a cream-colored face, chest, fingers, and toes. Its hands have five fingers, and its feet have three toes. Its fluffy, swirled tail resembles a flame. There is a flame flickering inside its body, which it fuels with sweet foods. It is also capable of scattering embers from its tail and the tufts on its head.
Simisear shares its category with Fletchinder. They are both known as the Ember Pokémon. In Japanese, the two Pokémon also share their category with Charcadet, namely ひのこポケモン Hinoko Pokémon (Sparks Pokémon).