Rotom is a dual Electric-Ghost-type that debuted in Pokemon Diamond/Pearl. With the enhanced version of Diamond/Pearl, Pokemon Platinum, Rotom could change its form and Typing with the help of the Rotom Catalog, which could only be obtained through an Event. In Pokemon Scarlet and Pokemon Violet, the Rotom Catalog isn't locked behind a special Event, which makes it much easier for players to change their own Rotom whenever they want.