From Japanese ピカチュウ (Pikachuu), derived from the onomatopoeic words ピカピカ (pikapika), a sparkly sound, and チュウチュウ (chuuchuu), a mouse sound. This is the name of a Pokémon, a yellow rodent-like creature who can summon electricity, from a series of video games starting 1996.

The name "Pikachu" comes from the Japanese words "pikapika" (the sound of electricity) and "chuchu" (the sound that a mouse makes).