Most of the time, Pokémon evolve just by battling and gaining XP. There are a few, though, that have special requirements for evolving, such as Gimmighoul. This little treasure-obsessed Pokémon comes in two base forms — either as the Pokémon alone holding a coin or hiding in a chest — but you can only catch and evolve the chest form. Here’s the price you’ll need to pay if you want to evolve Gimmighoul into Gholdengo.
Evolving Gimmighoul will require you to grind out quite a bit of cash.
Step 1: Collect 999 Gimmighoul Coins. These are obtained by finding either type of Gimmighoul (normal or chest form) and interacting with or battling them. You can’t catch the normal form. They can usually be found near ruins, bridges, and signs, and they will simply run away and leave behind a random amount of coins. Chest Gimmighouls have set spawn points and drop way more coins when you catch or beat them, but have a lesser chance of respawning each day.
Step 2: After getting 999 coins, simply level up your Gimmighoul once more, no matter what level they’re at, and they will evolve into a Gholdengo. Be aware that doing this will cause you to lose all 999 of your coins, meaning you will need to grind them up again if you want to evolve a second Gimmighoul.