Which artist designed a large majority of the original 151 Pokémon?

Ken Sugimori designed a large majority of the original 151 Pokémon.

Sugimori was Game Freak’s character designer and art director, and he created much of the visual identity of the first Pokémon games. His clean illustrations became the familiar reference artwork used in game materials, merchandise, cards, and promotional products.

Sugimori did not design every original Pokémon alone. Atsuko Nishida, Motofumi Fujiwara, Shigeki Morimoto, and Satoshi Ota also contributed to the first-generation designs. Nishida, for example, is widely associated with Pikachu’s design, while Sugimori served as the principal visual leader for the franchise’s early artwork.

This shared-credit history is why naming a single designer for every original species would be inaccurate. The precise fact is that Sugimori designed a large majority of the first 151, working alongside several other artists. His role also connected Pokémon’s creature designs to the wider history of Game Freak.