Talk:Saffron City/@comment-33569838-20171219002430/@comment-34668827-20171219030147

It has to do with the Pokémon anime.

“ Haunter, Ash, and Pikachu After Ash struggled to defeat Sabrina, Sabrina's father told him that Ghost Pokémon would probably be able to defeat Sabrina's Psychic minions and suggested going to the Pokémon Tower to find Gastly, Haunter, and Gengar. Ash found all three of them, but did not capture them. The Haunter that he befriended decided to follow him back to Saffron though, at the end of The Tower of Terror.

In Haunter versus Kadabra, Ash challenged Sabrina a second time; Haunter however disappeared. When Ash found it, Haunter disappeared once again, treating it all like fun and games. Haunter finally returns just as Kadabra was about to defeat Pikachu and proceeded to make Sabrina laugh. This made a connection to Sabrina's old self, unlocking her heart, and while she was immobilized by laughter at the Haunter's faces, her Kadabra, who was psychically linked with her, was immobilized as well. Ash and Haunter were subsequently given the Marsh Badge.

Haunter was later left with Sabrina at the Saffron Gym, to keep her under control.” -Bulbapedia