Marley

Marley is a minor character who appears in the Pokémon anime during the Diamond and Pearl series (specifically in the episode "Keeping In Top Forme!" / DP168).

She's a young Trainer with a quiet, somewhat mysterious demeanor. In the anime, she's first encountered when Brock rescues her from floating unconscious in a boat on a river (just before a waterfall). She travels with Ash, Brock, Dawn, and Pikachu for a short time to help protect and assist a Mythical Pokémon, Shaymin (in its Land Forme), which had ended up with her and was being pursued by Team Rocket.

Her appearance matches the games: she's a skinny girl with pale skin, short black hair tied with a white bow, blue eyes, and a gothic-style black-and-white outfit (thigh-length dress, black tights, and boots).

She doesn't speak very much and comes across as reserved, but she's kind-hearted and cooperative in helping Shaymin reach safety and eventually its home in the Flower Paradise area. Her role is brief and tied specifically to that Shaymin-focused storyline.