How to get a shiny Gyarados in Pokemon Scarlet

Catching a shiny Gyarados in Pokemon Scarlet isn't different from catching other shinies, but it does require patience! First tip: focus on areas where Gyarados is known to spawn. Next, take advantage of the 'Masuda Method' by breeding two Magikarps from different language games, which increases your chances of hatching a shiny. Don't forget to use a Shiny Charm if you have one, as it further boosts your shiny odds. Keep at it, and eventually, that red Gyarados will be yours!

I caught a shiny Gyarados by accident while I was actually looking for something else, lol. So, my advice? Just play the game and enjoy, shiny Pokémon will come when you least expect them!