From Bulbapedia, the community-driven Pokémon encyclopedia.
In the original Western releases of Pokémon Crystal, there is no way of obtaining the GS Ball, as no event equivalent to the one present in the Japanese version was ever offered to players of the Western versions of the game. Without the GS Ball, the Celebi event cannot be triggered. However, it is possible to obtain the item by hacking or exploiting [[glitch]]es within the game. Some game-enhancing devices, however, such as the [[GameShark]], can be used to generate the GS Ball right in the player's [[Bag]] in all versions of the game.
In the [[Virtual Console]] release of Pokémon Crystal, the GS Ball can be obtained without an event, allowing players to trigger the Celebi event at the shrine regardless of language.