Following on from Niantic's tease during the Pokémon GO Fest event in Germany, the troublesome Team Rocket has now started to invade the game, giving players a whole new reason to load up the app and get catching.

Since yesterday, players have been discovering black PokéStops which act in a very different way to your usual, item-grabbing stations. When you spin the disc on one of these altered PokéStops, a Team Rocket Grunt appears to take you on in a battle; win this fight, and you can catch a Shadow Pokémon.

It looks like sightings of discolored PokéStops have increased, as more Trainers have started to submit reports. Hmm... This is very troubling. — Pokémon GO (@PokemonGoApp) July 23, 2019

Shadow Pokémon are a little different to your usual 'mon; you'll notice that they have a shadow aura surrounding them and red eyes, and that they have lower-than-usual CP. You can choose to purify the Pokémon if you wish, with Candy and Stardust being used to boost its stats and return the Pokémon to normal.

Pokémon in the Bulbasaur, Charmander, Squirtle, Rattata, Zubat, Snorlax, Dratini, and Mudkip evolution chains have already been spotted in Shadow form, although we expect more will appear over time.

Have you encountered many of these mysterious PokéStops? Happy to see a new feature in the game? Let us know with a comment below.