Pikachu (Japanese name: ピカチュウ Pikachuu). The most famous Pokémon of all. ピカ (pika) comes from the word ぴかぴか (pikapika), meaning 'shiny', and チュウ (chuu) is the onomatopeia for the cry of mice. So Pikachu means 'shiny mouse'. Pikachuu, the 'shiny mouse'.

As it turns out, franchise artist Atsuko Nishida provided an explanation for it years ago. Nishida said Pikachu’s name came from the Japanese words “Pika,” an onomatopoeia for the sound of an electric spark, and “chu,” the sound mice make.