The Ghost girl is a minor character from Pokémon Diamond and Pearl: Battle Dimension.
The Ghost girl first appeared in the episode 'Ghoul Daze!'. She hid in bushes and came out when Conway came near, asking him to play with her. A night, Conway followed him but he was saved by a Dusknoir. She also tried to lure Meowth with food but Dusknoir stopped her again.
After that, she made Ash and Angie follow her into the Summit Ruins. She then tried to coax Ash and Angie into the mysterious cave that was actually the entrance of the Spirit World. Dusknoir tried to stop her but Ash and Angie started to defend her. At last, Dusknoir blasted the girl into the spirit world and collapsed the cave entrance trapping her inside, forever.
- The Ghost girl appears in the book Pokemon Chapter Book #1, a novelization of the episode.