In Pokémon Pokopia, what object does Ditto find from its former trainer?

Ditto finds its former trainer’s old Pokédex in Pokémon Pokopia.

The old Pokédex is an important story object because it connects Ditto’s present journey with the human world that has disappeared. After finding it, Ditto assumes a form based on its former trainer and begins helping investigate the abandoned environment.

This discovery supports the game’s central mystery. Humans have left the region, Pokémon habitats have become uninhabitable, and records left behind gradually reveal what happened. The Pokédex therefore functions as more than a familiar Pokémon gadget: it is a link to Ditto’s past and to the missing trainer.

The object should not be confused with the game’s broader Pokédex features, such as cataloguing Pokémon. The specific plot detail is that Ditto finds an old Pokédex belonging to its former trainer.