I remember playing around with the Pokémon mini in Pokemon Channel (for GameCube).
I'm pretty sure you're talking about either the Pokémon Pikachu or Pokémon Pikachu 2 GS, not the Pokémon mini:
http://en.wikipedia.org/wiki/Pok%C3%A9mon_Pikachu
I still have mine... in fact, I kinda forgot about...