Pokémon Pokopia’s playable character’s original Pokémon form is Ditto.
The character appears human-like because Ditto has transformed to look like a human. This setup is central to Pokopia’s identity: the player is not controlling an ordinary human builder but a Pokémon using transformation as part of its everyday life and work.
Ditto’s role also connects the story to the game’s wider theme of adaptation. The world needs to be restored through collecting, construction, farming, cooking, and cooperation with other Pokémon, and the protagonist’s transformation gives the player a human-shaped way to perform those activities.
Zorua and Mew are sometimes suggested because they are also associated with unusual appearances or illusions, but they are not the playable character’s original form in Pokopia. The specific answer is Ditto, the Normal-type Pokémon known for transforming into other forms.