The first method is through the Poké Radar, which is an item that can be obtained by defeating Team Galactic's Charon in the Valley Windworks. Once you have the Poké Radar, go to a body of water and use it. If a wild Pokémon appears on the screen, press A to start a battle. If the wild Pokémon is a Magikarp and it is shiny, you will immediately see it. If it is not shiny, you can reset the game by pressing L+R+A+Start+Select all at the same time, and then try again.
The second method is through chaining. Chaining involves encountering the same Pokémon in a row without letting any other Pokémon appear in between. If you chain 40 Pokémon in a row, you will have a 1/200 chance of encountering a shiny Magikarp.
Here is a step-by-step guide on how to chain for a shiny Magikarp in Pokémon Pearl:
-Go to a body of water where Magikarp can be found.
- Use the Poké Radar until a wild Magikarp appears.
- If the Magikarp is not shiny, reset the game by pressing L+R+A+Start+Select all at the same time.
- Repeat steps 2 and 3 until you have chained 40 Magikarp in a row.
-After you have chained 40 Magikarp in a row, the next Magikarp that you encounter will have a 1/200 chance of being shiny.