Simisear is a bipedal monkey-like Pokémon. Most of its fur is fiery reddish in color, and it has yellowish tan fur on its face, belly, fingers, and toes. It has ovular eyes with black pupils, a round black nose, and long rounded ears (with orange insides) that are quite large compared to the size of its head. Unlike its pre-evolution, Pansear, Simisear has more hair atop its head; the tufts of red fur on its head resemble flames. Its thin arms protrude from shoulders that are covered in fluffy white fur that resemble clouds of steam, alluding to its fiery, volcanic nature. It has thick furry red tail that resembles a swirling flare of red flames. It has a plump, rounded belly that is mostly yellowish-tan; the lower part of its belly is red with a zigzagging pattern separating it from the tan fur on its upper belly.
Simisear is a very hot-tempered Pokémon that is easily angered. It loves to eat sweets because the sugars fuel the fire blazing inside its belly, providing it with much energy for battle. When it becomes excited, embers rise from its head and tail, which rapidly increase in temperature.
A flame burns inside its belly (much like Pignite), and eating sweets fuels this internal flame. It scatters the embers that sprinkle from its head to sear its opponents in battle.
Simisear, along with Simisage and Simipour and their respective pre-evolutions are the only Pokémon able to get the abilities solely used by the starter Pokémon. Simisear gains the ability Blaze, previously only attained by Fire-type starters.
Chili's hairstyle slightly resembles that of Simisear's.
Simisear is based on a monkey and a flame.
Simisear's English name is a combination of the words "simian" and "sear".