DJ Rotom is the Pokémon Pokopia special character who possesses a stereo system.
Rotom is known for possessing electrical appliances, and Pokémon Pokopia uses that concept to create DJ Rotom. The character’s defining host object is a stereo system, giving the character a music-themed identity within the game’s cast of unusual Pokémon.
DJ Rotom appears alongside other named special characters encountered as Ditto restores habitats. These include Mosslax, a Snorlax covered in vegetation; Chef Dente, a Greedent associated with a chef trainer; Smearguru, a gifted Smeargle artist; and Tinkmaster, a Tinkaton who uses tools.
DJ Rotom is the precise character name. “Rotom” alone identifies the species, while “stereo” describes the possessed appliance, so neither is as specific as the full in-game name.