I know that the main protagonists name is サトシ after Satoshi Tajiri (田尻智), the creator himself but his name was changed to Ash Ketchum (same with how タケシ became Brock, ヒカリ (光) was called Dawn, カスミ (霞) became Misty, and so on). ゼニガメ (from 銭亀 = “baby spotted turtle”) was adapted to Squirtle or フシギダネ is renamed as Bulbasaur, ヒトカゲ is known as Charmander in ENG.


Well there you have a perfect example. “baby spotted turtle” is quite the mouthful and doesn’t really work well as a name in English.