Lance's Gyarados (anime)

Lance's Gyarados is a shiny Gyarados owned by Lance.

Games
Lance's Gyarados is a wild Shiny Pokémon that appears in Gold, Silver, and Crystal games, the player has a chance to capture Red Gyarados at the Lake of Rage.

Anime
It first appeared where due to Team Rocket's operation upon Lake Pokémon made a shiny Magikarp to evolve. Lance caught it after battle with Dragonite.