Jessie (Japanese: ムサシ Musashi) is a member of Team Rocket, more specifically part of a trio with James and Meowth, that follows Ash and his friends around in the Pokémon anime, usually trying to steal Ash's Pikachu.
So basically this is gonna be sorting fictional characters into groups/teams/associations of any sort they were apart of during their respective canon. Make sure to clarify for teams with multiple incarnations in different media which one you’re talking about.
