The Fire Doll is an enemy in Final Fantasy IV: The After Years. It is a magical construct created by Palom to test Leonora's skills in Black Magic. It does not fight back and only serves as a target for Leonora to cast her "Fire?" spell on. Depending on Leonora's level, this may take more than one casting.
Fire is the rapid oxidation of a material in the exothermic chemical process of combustion, releasing heat, light, and various reaction products.