In its Land Forme, aside from being timid and bashful, Shaymin can be capricious and a bit arrogant, despite having an adorable appearance. It has a habit of unwilling to budge for the slightest when being carried on Ash's head, and likes eating Dawn's Poffins.
In its Sky Forme, Shaymin is bolder, braver, and more outgoing.
Shaymin is known as the Gratitude Pokémon. After Shaymin was pulled into the Reverse World by Giratina and was in the middle of it's battle with Dialga, it used Seed Flare to create a portal out of the dimension. This strange experience caused Shaymin to become terrified of almost everything. It also constantly referred to Gracidea, and was convinced that Giratina wanted to eat it when the Renegade Pokémon really wanted to use Shaymin to open a portal to the real world.
Shaymin found its way to Ash and his friends after its frightening ordeal with Giratina, attracted by the panackes Brock had prepared. Ash, Dawn, and Brock agreed to take Shaymin to Gracidea, where it and its friends would all change forme together. However, Zero took notice of Shaymin's ability to make a portal connecting the Reverse World and the real world and made several attempts to seize it, hoping to use Shaymin's power to capture Giratina. With the help of Ash and his friends, Shaymin transformed into its Sky Forme after being exposed to the Gracidea and drove away Zero's Pokémon. Eventually, Zero was defeated permanently when Shaymin, Giratina, Ash, and Ash's Pokémon followed him into the Reverse World and put a stop to his plans.
After peace had been regained, Shaymin's friends arrived at Gracidea and joined it as they all changed to their Sky Forme and flew away together.
- Vanilla Yamazuki (Japanese)
- Amy Palant (English)
- In the Japanese dub, Shaymin when in its Land Forme refers itself with "Mi" as its pronoun, and ends its sentences with "deshou". Whereas in Sky Forme, it ends its speeches with "desu".