|Episode First Shown in||Unfair Weather Friends|
|First Known Owner||Bart|
|First Game Appeared in|
|National Dex Number||351|
In its natural form, Castform is small, gray and slightly resembles a cloud. When it is sunny, Castform's lower half becomes white while the head turns orange with small orange balls around it. This gives Castform's head a shape that is similar to the sun. During rain, Castform's lower half becomes a darker shade of gray. The head is blue, resembling a drop of rain. In hail or snowy weather, Castform's head turns purplish-blue. The rest of the body changes into a mint green cloud, that also appears to resemble a decorative ice sculpture. Castform does not have a form for sandstorms or fog. In all forms, Castform has markings around its eyes similar to a pair of glasses.
In Intimas, Castform has a sand form, which is his head, which is a brown color, and his mask-like pattern is a reddish-brown. He has a cone-like extension under it, and it has a swirl of sand on its head. It has sand swirping around him.
- Bart's Castform appeared in the episode Vs. Castform.
- A coordinator's Castform appeared in Vs. Hoenn Grand Festival.
- Water Gun
- Powder Snow
- Rain Dance
- Sunny Day
- Weather Ball
- Hydro Pump
- Fire Blast