DJ Rotom is the Pokémon Pokopia character who has possessed a stereo system.
DJ Rotom is a special Rotom encountered in the story. Rotom is an Electric/Ghost-type Pokémon famous for possessing household appliances, so the stereo system is a fitting extension of the species' established concept.
In Pokopia, the character's identity is presented through the nickname DJ Rotom. The character is listed with other distinctive residents such as Professor Tangrowth, Peakychu, Smearguru, Mosslax, Chef Dente, and Tinkmaster. These named Pokémon help give the restored world its own local personalities.
Rotom was introduced in Generation IV and can take on different appliance forms in the main series. Pokopia uses that possession theme in a more social and decorative context, connecting Rotom to music and the player's developing Pokémon community rather than making it only a battle mechanic.