Chespin is a bipedal, mammalian Pokémon. It is primarily light brown with darker arms and three triangular markings around its face. It has oval, brown eyes; a triangular, red nose; and rodent-like incisors. Its arms have three fingers, while its feet have two long claws. Covering its back is a tough, green shell, which extends from its head to halfway down its tail. The tip of its tapered tail is orange. There is a small, off-center hole in the shell on the back of Chespin's head and, around the face, the shell has four leaf-like spikes. On the back of its head is another spike split into three parts.
Chespin's shell can protect it from powerful attacks. The quills on its head are usually soft but can be stiffened for attacking as well. Despite having a curious nature that tends to get it in trouble, Chespin keeps an optimistic outlook and does not worry about small details.
Chespin appears as a trophy in both the 3DS and Wii U versions of the game.
NA:Chespin, the Spiny Nut Pokémon. This Grass-type Pokémon is one of the new Pokémon you can choose when starting a new adventure. The spikes on its head could stop a truck. It can evolve into Quilladin. Its Seed Bomb move will scatter bombs around it that instantly explode.
PAL:Chespin, the Spiny Nut Pokémon. This Grass-type Pokémon is one of the ones you can choose at the start of Pokémon X and Y. The thick shell covering its head and back is so strong, it can protect Chespin's body from almost any impact. Its Seed Bomb attack will scatter bombs around it that instantly explode.
The brown spot found on the back of Chespin's head may be a subtle reference to Bend-Or spots, most commonly found on a chestnut horse. Bend-Or spots occur in breeds with chestnut coloration, and most chestnuts seem to have at least one.
Chespin is a combination of chestnut and pin. It may also be from urchin (an old term for hedgehog), chinkapin (the name of some species of chestnuts), and spina (Latin for thorn).
Harimaron is a combination of 蝟 harinezumi (hedgehog), 針 hari (needle), and marron (French for chestnut).