The latest update to Pokémon Go adds Shadow Pokémon to the game thanks to Team Rocket. These Pokémon are not so different than any other monsters, but they’ve succumbed to anger and darkness to try to be stronger for their Team Rocket trainers.

Shadow Pokémon take center stage in a new Special Research called, “A Troubling Situation.” Among the many tasks involved is capturing and purify Shadow Pokémon from Team Rocket. Encountering these new creatures and trainers requires you to find them at certain Pokéstops and engaging in battle. Once defeated, players have the chance to capture and purify these Shadow Pokémon.

These monsters also come knowing Frustration, a move that traditionally does more damage the more the Pokémon dislikes you, but once purifying them from their shadows, that move will turn into Return, a move that does more damage the more the Pokémon loves you. However, Pokémon Go doesn’t have Pokémon friendliness modifiers, so they both do a flat amount.

How do I get a Shadow Pokémon?

To catch a Shadow Pokémon, you have to go to a Pokéstop that’s taken over by Team Rocket. You’ll battle the grunt, and if you win, you’ll get a chance to catch the Shadow Pokémon they were using.

How do I get more balls to catch Shadow Pokémon?

When you go to catch your first Shadow Pokémon, you may only get 4 or 5 Premiere Balls to do the job. Just defeating the Grunt will get you 2, and you’ll get an additional ball for every Pokémon you have still standing at the end of the fight.

There are two other sources that’ll increase your Premiere Balls: Hero and Purifier. When you start out, you’ll always see these listed as +0 balls at the end of the fight. They are tied to two medals with the same names. Getting the Bronze Hero medal requires defeating 10 Grunts in total. Getting the Bronze Purifier medal requires purifying 5 Shadow Pokémon. Both of these should come naturally.

As you move up the ranks in each of these medals, you’ll get more balls to catch Shadow Pokémon with.

How do I purify Shadow Pokémon ?

To purify Shadow Pokémon, you simply have to hit the button on their information screen. Purifying costs dust and candy, but it’s a pretty simple process.

What’s the difference between Purified Pokémon and Pokémon I catch?

Purified Pokémon cost less candy to evolve and less dust to power up. They also know Return, a normal-type attack. While Return is OK on a normal-type Pokémon, it’s not super great on anything else and can be replaced.

Purified Pokémon also get IV boosts when powered up. Each stat goes up by two when purified, meaning if you catch a Shadow Pokémon with at least 13 Attack, Defense, and Stamina will turn into an 100-percent IV Pokémon.

What Pokémon can be Shadow Pokémon?

As of July 22, the only Pokemon that can be caught as Shadow Pokémon are Charmander, Squirtle, Bulbasaur, Rattata, Zubat, and Snorlax.

Update (July 23): A previous version of this guide listed more Shadow Pokémon available. These Pokémon have been datamined, but not yet released. The guide has been updated to list only the currently obtainable Shadow Pokémon.

Update (July 25): Adding information about how to get more Premiere Balls when catching Shadow Pokémon.