From Bulbapedia, the community-driven Pokémon encyclopedia.
This is a reverse-chronological list of Nintendo event Pokémon that were given away in 2004 for all Japanese Pokémon games.
List of event Pokémon
All Nippon Airways Pikachu
PCJP Distribution #2
These four Pokémon were given away as Eggs at the Pokémon Center stores in Japan; all of them know a special move. They were available to Pokémon FireRed and LeafGreen players from March 24 to April 4, 2004. The Pokémon may have been hatched in another game before being sent to Pal Park, and so they may have arrived from either Kanto or Hoenn.
The Zigzagoon received is dependent on the player character's gender instead of the version of the game the player is playing.