Pikachu creator Ken Sugimori
Pikachu is a fictional species in the Pokémon media franchise. Designed by Atsuko Nishida and Ken Sugimori, Pikachu first appeared in the 1996 Japanese video games Pokémon Red and Green created by Game Freak and Nintendo, which were released outside of Japan in 1998 as Pokémon Red and Blue. Pikachu is a yellow, mouse-like creature with electrical abilities. It is a major character in the Pokémon franchise, serving as its mascot and as a major mascot for Nintendo.
Pikachu is widely considered to be the most popular and well-known Pokémon species, largely due to its appearance in the Pokémon anime television series as the companion of protagonist Ash Ketchum. In most vocalized appearances Pikachu is voiced by Ikue Ōtani, though it has been portrayed by other actors, notably Ryan Reynolds in the live-action animated film Pokémon Detective Pikachu. Pikachu has been well received by critics, with particular praise given for its cuteness, and has come to be regarded as an icon of Japanese pop culture.Concept and design
Developed by Game Freak and published by Nintendo, the Pokémon series began in Japan in 1996, and features several species of creatures called "Pokémon" that players, called "trainers", are encouraged to capture, train, and use to battle other players' Pokémon or interact with the game's world. Pikachu was one of several different Pokémon designs conceived by Game Freak's character development team. Artist Atsuko Nishida is credited as the main person behind Pikachu's design, which was later finalized by artist Ken Sugimori. According to series producer Satoshi Tajiri, the name is derived from a combination of two Japanese onomatopoeia: ピカピカ (pikapika), a sparkling sound, and チューチュー (chūchū), a sound a mouse makes. Despite its name's origins, however, Nishida based Pikachu's original design, especially its cheeks, on squirrels. Developer Junichi Masuda noted Pikachu's name as one of the most difficult to create, due to an effort to make it appealing to both Japanese and American audiences.Pikachu was designed around the concept of electricity. They are creatures that have short, yellow fur with brown markings covering their backs and parts of their lightning bolt-shaped tails. They have black-tipped, pointed ears and red circular pouches on their cheeks, which can spark with electricity. They attack primarily by projecting electricity from their bodies at their targets. Within the context of the franchise, Pikachu can transform, or "evolve," into a Raichu when exposed to a "Thunder Stone." Pikachu was originally planned to have a second evolution called Gorochu, which was intended to be the evolved form of Raichu. In Pokémon Gold and Silver, "Pichu" was introduced as an evolutionary predecessor to Pikachu. In Pokémon Diamond and Pearl, gender differences were introduced; since those games, female Pikachu have an indent at the end of their tails, giving the tail a heart-shaped appearance.
Initially, both Pikachu and fellow Pokémon Clefairy were chosen to be lead characters for the franchise merchandising, with the latter as the primary mascot to make the early comic book series more "engaging". Production company OLM, Inc. suggested Pikachu as the mascot of the animated series after finding that Pikachu was popular amongst schoolchildren and could appeal to both boys and girls, as well as their mothers. Pikachu resembled a familiar, intimate pet, and yellow is a primary color and easier for children to recognize from a distance. Additionally, the only other competing yellow mascot at the time was Winnie-the-Pooh.Pikachu's design has evolved from its once-pudgy body to having a slimmer waist, straighter spine, and more defined face and neck; Sugimori has stated these design changes originated in the anime, making Pikachu easier to animate, and were adopted to the games for consistency. "Fat Pikachu" 
was revisited in Pokémon Sword and Shield, where Pikachu received a Gigantamax Form resembling its original design.
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