Team GO Rocket and Shadow Pokémon
In July 2019, a new evil force
Team GO Rocket arrived in Pokémon GO, based on Team Rocket from the original Gen 1 games. Team GO Rocket have captured Pokémon and overpowered them by unnatural means, turning them into Shadow Pokémon. Rocket Grunts hide out at Poké Stops, causing them to turn dark and pulsate; however they disappear after 30 minutes. The Grunts steal resources from the stops and you must battle them to obtain the remaining items and save the Shadow Pokémon.
Once defeated, the Grunts abandon one of their Shadow Pokémon and it can be caught. Shadow Pokémon are initially low-level and the only charge move they can have is Frustration. However, through a process called Purification they can be saved. Purified Pokémon increase to level 25, gain 2 IVs in each stat (so a 13/13/13 Pokémon will become perfect), and will know the move Return instead of Frustration.
An additional facet to GO Rocket began in November 2017. After battling Rocket Grunts, a
Mysterious Component is obtained; combining six of them creates a
Rocket Radar which provides an encounter Team GO Rocket Leaders: Arlo, Cliff and Sierra. Through various Special Research the big boss of Team Rocket, Giovanni, can also be battled.
Team GO Rocket lineups
Each Rocket Grunt specializes in one Pokémon type - prior to the battle they give a message that hints at what type they will use. Battles are in the PvP format, however the Shadow Pokémon they use have massive CP - much higher than their usual maximum - so come prepared!
Team GO Rocket Leaders
After combining the Mysterious Components into the Rocket Radar, the Rocket Leaders can be seen at certain stops. Unlike Grunt takeovers, the Leaders stay at the same stop all day (8am-10pm), then will rotate to different stops the next day. No Grunt takeovers will happen at that stop, while a Leader is there.
Jesse & James started appearing in July 2020, when a new Rocket Balloon feature was added. If a Meowth balloon appears you battle them both in succession. They left at the end of September 2020.
Giovanni can only be encountered by obtaining the Super Rocket Radar via Special Research, and will reward a shadow Legendary. Sometimes a Decoy Grunt will appear instead of Giovanni.
All the Shadow Pokémon in Pokémon GO are listed below, with the Stardust and Candy required to purify them. Not all are currently available as the team rosters for Rocket Grunts change regularly, and some are only used as second/third Pokémon so are not obtainable.