Charla

Charla is a Charizard that lives in Charicific Valley and belongs to Liza.

Charla belongs to Liza, who maintains the Charicific Valley. Ash, Misty, and Brock got the chance to meet Charla while wandering through the Valley. Charla is Liza's only Pokémon, and her greatest partner, seeing as it travels with her to places outside the valley.

Romance
In Great Bowls of Fire, it was revealed that Ash's Charizard became Charla's bodyguard and it's apparent that Charla has fallen for it.