Pikachu Was Chosen as the Mascot Near the End of the Game’s Development
While Pikachu may nowadays be the worldwide mascot of the Pokemon series, the original mascot was actually going to be Clefairy. Game Freak changed the series mascot to Pikachu because they apparently felt that while Clefairy would only appeal to girls, Pikachu would appeal to everyone.
While Pikachu may have stolen Clefairy’s role as the series mascot, that hasn’t stopped Clefairy because it, along with Pikachu, were the main character’s starter Pokemon in the earliest Pocket Monsters manga. Oh and his Clefairy could talk too!