Castform

Castform (Japanese: ポワルン Powalen) is an artificial Pokémon introduced in Generation III. It is a Normal-type Pokémon with an appearance resembling a gray cloud with a single wisp on top of its head. Castform is notable for its ability to change forms and types based on the weather. In harsh sunlight, it transforms into its Fire-type Sunny Form, becoming orange and emitting heat. When it rains, it shifts into its Water-type Rainy Form, turning blue and becoming moist. During hail, it becomes its Ice-type Snowy Form, appearing pale green and icy. These transformations are not controlled by its will, but are a result of its cellular structure reacting to temperature and humidity. Despite being artificial, Castform can be found in grassy areas. It does not evolve, but its unique weather-based abilities and Forecast Ability make it a distinct Pokémon. Castform has appeared in anime, manga, and games, gaining popularity for its cute appearance and unique ability.