They tend to usually use Patrat, Sandile, Scraggy, Purrloin, and Trubbish along with their respective evolutions. In Pokémon Black 2 and White 2, they are seen with a more diverse pool of Pokémon, using Pokémon from other regions, mainly consisting of Normal, Poison, and Dark type Pokémon. They share a majority of their non-Unova Pokémon with the members of Team Rocket.
In the games
In Pokémon Black and White, Team Plasma Grunts act hypocritically, as they fight for Pokémon liberation yet keep their own Pokémon to battle with. They defend themselves saying that their purposes are different from those from the regular Tainers, and that's why they use them; unlike N, who seems to catch nearby wild Pokémon for battle and release them after, as well as the Seven Sages, who refrain from battling and call upon Grunts instead. In fact: N, Ghetsis and Grunts, are the only Team Plasma members to even battle the player. Although they preach living in peace with Pokémon, some of them still abuse Pokémon, such as two grunts kicking a Munna for its Dream Mist. They also treat Pokémon as tools, such as when one grunt states that N's Castle was built by overworking the Pokémon they had captured. In Pokémon Black 2 and White 2, Team Plasma is broken into two different forces, each with different purposes. One force still vows to release all Pokémon from their Trainers. Ghetsis is the leader of the newer force, which intends to take over Unova.
In the anime
Several Plasma Grunts are set to make an appearance in their pirate outfits in BW112, an episode of the upcoming Best Wishes! Season 2: Episode N.