Rotom (Japanese: ロトムRotomu) is an Electric/Ghost-type Pokémon. In some Pokémon Books it is classified as a Legendary Pokémon. Rotom can possess various appliances, allowing it to take on five other forms:
Heat Rotom: A form attained by possessing an oven and is part Fire-type.
Wash Rotom: A form attained by possessing a washer and is part Water-type.
Frost Rotom: A form attained by possessing a refrigerator and is part Ice-type.
Fan Rotom: A form attained by possessing a fan and is part Flying-type.
Mow Rotom: A form attained by possessing a lawnmower and is part Grass-type.
Rotom is a ghost made of plasma, allowing it to possess various electronic devices and is commonly found inside of a television in the Old Chateau. In Pokémon Platinum, Rotom gains the ability to take on five other forms, each changing depending on the appliance it is possessing: Heat, Wash, Frost, Fan and Mow. Prior to Generation V, all of its forms were Electric/Ghost-type.
It may be based on a Poltergeist or on the philosophical term, "ghost in the machine". Rotom's may also be based on a species called Obake, which are objects that become animate when reaching their 100th year of existence, and a Bakemono, which is referring to a state of transformation or shape-shifting.
Rotom's name is actually the word "motor," spelled backwards, due to the fact that all of the household appliances it can turn into have motors. It is one of the few Pokémon whose name is a palindrome. Rotom's name could also be a combination of rotor and phantom, which is another word for ghost.
The Secret Key, which is obtained in a Nintendo Wi-Fi event, looks a lot like Rotom, minus the "arms".
Rotom is one of three Ghost-types whose Pokédex color isn't in the black or purple category, which means it has no predominant purple or black coloring. The others are Shedinja (brown) and Froslass (white).
Rotom's new forms are only available in Platinum and beyond. When traded to any other versions, it automatically reverts to its original form.
Rotom changes its forms in a similar fashion to Deoxys in the Generation IV games.
Rotom is the only Pokémon with the ability to change its form by will that must possess another object in order to do so. Castform, Deoxys, Giratina and Shaymin actually transform their bodies. However, Burmy is similar to Rotom in that it merely changes its surrounding cover.
Rotom is the only Pokémon whose alternate forms have a different base stat total than that of the original form. Other Pokémon with alternate forms may have different distributions, however.