Pokémon Red and Green Versions/Development

Pokémon Red and Green had many pre-release elements that differ from the final release, although the international would later have several altered aspects of their own during the two-and-a-half years between the release of Red and Green, their bug-fixing release, and the release of the merger of the trio into Red and Blue for overseas markets.

An error made during development causes the depicted during Professor Oak's introductory lecture to be a  but with the cry of a. It was not fixed in the Japanese Blue or in the international Red and Blue.