Pikachu (Japanese: ピカチュウ Pikachu) is an Electric-type Pokémon introduced in Generation I. It evolves from Pichu when leveled up with high friendship and evolves into Raichu when exposed to a Thunder Stone. In Alola, Pikachu evolves into Alolan Raichu when exposed to a Thunder Stone. Pikachu has sixteen alternate forms that fall into four groups: Cosplay Pikachu, Pikachu in a cap, the partner Pikachu, and Gigantamax Pikachu. Ordinary Pikachu can Gigantamax into Gigantamax Pikachu if it has the Gigantamax Factor. Additionally, many other Pikachu variants have appeared in various media. Cosplay Pikachu, Pikachu in a cap, the partner Pikachu, and Pikachu with the Gigantamax Factor cannot evolve. The Pikachu received at the beginning of Pokémon Yellow will refuse to evolve into Raichu unless it is traded and evolved on another save file. Pikachu is popularly known as the mascot of the Pokémon franchise and one of Nintendo's major mascots. It is also the game mascot of and the player's first Pokémon in Pokémon Yellow and Let's Go, Pikachu!, the player's first Pokémon in Pokémon Rumble Blast and Pokémon Rumble World, and has made numerous appearances on the covers of spin-off games.