Castform

Castform is a Normal, Fire, Water or Ice-type Pokémon from the Hoenn region depending on what form it is. It does not evolve into or from any other Pokémon. It has four different forms namely Normal, Sunny, Rainy and Snowy, which are weather dependent.

Possible attacks
Normal form=

Attack availability
Sunny form=
 * Normal-type Weather Ball:  added  on March, 2019,  removed  on May , 2021,  added  back on August , 2021
 * Rock-type Weather Ball:  added  on May, 2021

Attack availability
Rainy form=
 * Weather Ball:  added  on March, 2019

Attack availability
Snowy form=
 * Weather Ball:  added  on March, 2019

Attack availability

 * Weather Ball:  added  on March, 2019

Forms
Castform has four different forms, varying in types and moves. Each of these forms spawns in specific weather conditions. Regular=

Shiny= PS Castform PS Castform PS Castform PS Castform

Availability

 * Castform spawns in wild in a form corresponding to the weather:
 * It spawns with Normal form when it is Partly-cloudy, Cloudy (overcast) or Windy.
 * It spawns with Sunny form when it is Sunny (clear weather).
 * It spawns with Rainy form when it is Rainy.
 * It spawns with Snowy form when it is Snowy or Foggy.
 * Castform in wild remains in the form corresponding to the weather at the time, that it has spawned, even if the weather changes, so it might occur that Castform's form does not correspond to current weather when player encounter it.
 * It spawns with Normal form when it is Partly-cloudy, Cloudy (overcast) or Windy.
 * It spawns with Sunny form when it is Sunny (clear weather).
 * It spawns with Rainy form when it is Rainy.
 * It spawns with Snowy form when it is Snowy or Foggy.
 * Castform in wild remains in the form corresponding to the weather at the time, that it has spawned, even if the weather changes, so it might occur that Castform's form does not correspond to current weather when player encounter it.

Trivia

 * Unlike in the Pokémon games of main series, Castform remains in the form it is captured as.
 * Coloring of Castform Candy was updated on August, 2018 to reflect more appropriate colors of Castform.
 * The Castform forms used by the Team Leaders in their battle parties mistakenly use the moves of Normal Castform. For example, Candela's Sunny Castform can use Hex and Energy Ball, which cannot be learned by Sunny Castform.
 * Initially, Castform was the only Pokémon to have no shiny variants for its different forms other than Normal one. Sprite assets for shiny variants of Sunny, Rainy and Snowy forms were added to the game in September 2020.
 * These shiny variants were also absent in the main core game series, until Pokémon HOME which was released back in February 2020.
 * Due to an error, Normal-type Weather Ball for Normal Castform was changed to Rock-type Weather Ball on May, 2021. Normal-type Weather Ball was later re-introduced at the start of GO Battle League Season 9.