Green appears after the player becomes Champion in Pokémon: Let's Go, Pikachu! and Let's Go, Eevee!. Trace mentions a girl hunting a powerful Pokémon in Cerulean Cave, and once the player has caught Mewtwo, Green is found standing where it used to be. She first throws a Poké Ball at the player, mistaking them for a Pokémon, then demands a battle when she learns Mewtwo is already taken.
Beaten, she hands over both of Mewtwo's Mega Stones, Mewtwonite X and Mewtwonite Y, and then tries to recruit the player as one of her Pokémon by pelting them with more Poké Balls. Her team is Clefable, Gengar, Victreebel, Ninetales, Kangaskhan and a Blastoise she Mega Evolves at the first opportunity. She can be rematched in Cerulean City every time the player beats the Pokémon League.
Green's look traces back to an unnamed girl Ken Sugimori drew for the 1996 Red and Green strategy guide. That design was adapted into Green, the trickster heroine of the Pokémon Adventures manga, then into Leaf, the female player in FireRed and LeafGreen, and finally into this Let's Go character. English releases call her Green because in Japan she is Blue, the name taken by the rival in Western versions. She also appears in the Pokémon Evolutions web series and as an opponent with Blastoise in Pokémon UNITE events.
Our catalog lists 2 Green cards in 1 set, both Green's Exploration from Unbroken Bonds (2019), an Uncommon and a full-art Ultra Rare, each illustrated by Naoki Saito. The Supporter searches the deck for up to 2 Trainer cards, but only when you have no Pokémon with Abilities in play.
The regular Uncommon printing of her Supporter, illustrated by Naoki Saito.
The full-art Ultra Rare version from the same set, also by Naoki Saito.
No. Green's Japanese name is Blue, but she is a separate character from Blue, the rival of Red, whose Japanese name is Green.
In Cerulean Cave after catching Mewtwo, once the player is Champion; she gives the player Mewtwonite X and Mewtwonite Y after losing.
Our catalog lists 2 Green cards, both named Green's Exploration, from Unbroken Bonds (2019).

TRAINER
2 Trainer cards · 0 partner Pokémon
Green is the Mewtwo-chasing Trainer from Pokémon: Let's Go, Pikachu! and Let's Go, Eevee! (2018), known as Blue in Japan and the game version of the heroine of the Pokémon Adventures manga. Her card is the Supporter Green's Exploration from Unbroken Bonds (2019).
No published index yet — too few of Green’s cards trade often enough to strike one.