Jynx has an alteration in the re-releases of Pokémon Gold and Silver. Akin to Pokémon Yellow, Jynx’s sprite has been altered in the Game Boy Color classics. Jynx’s sprite was initially altered in the International versions of Pokémon Gold, Silver and Crystal, while its original sprite remained in the Japanese versions. However, with this week’s Virtual Console release, the Japanese versions have altered the sprite of Jynx to match the international releases. You can check out a screenshot of the altered Jynx in the image above.
Source: Serebii