| Koga's Gastly|
キョウのゴース Kyou's Goosu
|Debut:||Sigh for Psyduck|
|Current location:||With Koga|
Blue and Charmeleon went to the Pokémon Tower in Lavender Town to fight Koga. However, Koga sent Gastly, who managed to manipulate Blue and Charmeleon, causing them to stand ground and attack anyone. Charmeleon used Fire Spin on Red, whose Bulbasaur blew a wind to redirect the attack to Gastly, who left, causing Blue and Charmeleon to regain consciousness.
None of Gastly's moves are known.