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 and its pre-evolution are the only non-starter Pokémon to have Blaze as a legally obtainable Ability, albeit only as a Hidden Ability.
Simisear is based on a monkey and a flame, though its midsection's pattern, cloud- or steam-like appendages and flame-like appendages make it similar in appearance to an active volcano. It, along with its two contemporaries, seem to be inspired by the three wise monkeys motif; with its large ears, Simisear represents "hear no evil".