Pikachu is probably the most iconic and recognizable of all of the 800+ Pokémon that Game Freak has created over the years. The adorable little ball of yellow goodness is categorized as a "Mouse" Pokémon, and its name would suggest a correlation to the pika, but as it turns out, Pikachu was primarily inspired by another animal: the squirrel.
Atsuko Nishida is a former Game Freak employee who helped create numerous Pokémon as a graphics designer. Nishida is credited as the primary creative force behind Pikachu's design, before it was finalized by artist Ken Sugimori. In a recent interview with Yomiuru, Nishida opened up about Pikachu's inspiration. As it turns out, Nishida had squirrels on the brain.
"At that time, I was really into squirrels, so I wanted the character to have puffy cheeks. Squirrel tails are cute (so I wanted it to have a tail). However, I wanted the character to have a lightning element, so I made it shaped like lightning."
"I didn't have a squirrel, but at that time, I wanted to have one. It's not like squirrels were popular [in Japan] then. I like animals, and then I had a ferret and a turtle at home. Since I thought the ways squirrels moved were comical and cute, I wanted one." — Atsuko Nishida
One of Pikachu's well-known traits is storing up and releasing electricity from the red spots on his rosy cheeks. This idea, Nishida says, was based on the way the cheeks of squirrels bulge out when they stuff their mouths with food. The Pokémon team would eventually settle on the name Pikachu and the category of "Mouse" or "Electric Rodent" for Pikachu, distancing the beloved character from his squirrely origins.