Roxie made her appearance in "Rocking the Virbank Gym! (Part 1)" and "Rocking the Virbank Gym! (Part 2)". She is a formidable Gym Leader who managed to defeat every challenger with just three Pokémon. Upon Ash's arrival at her Gym, she was excited to see his Pikachu, as she also had a Pokémon from Kanto, Koffing, and eagerly accepted his challenge.
Roxie demonstrated herself to be a highly capable Gym Leader, overcoming five out of Ash's six Pokémon even though she was at a disadvantage with her team. During the battle, she would occasionally play a riff on her bass guitar, prompting the crowd to chant her name. When she was defeated, she cheerfully congratulated Ash as the audience celebrated his victory. She then presented him with his eighth and final Unova Badge, the Toxic Badge.
(Source: Bulbapedia)










