Which Pokémon co-stars with Ditto as the environmental researcher in Pokémon Pokopia?

Professor Tangrowth co-stars with Ditto as Pokémon Pokopia’s environmental researcher.

Professor Tangrowth is a Tangrowth who studies the ruined environment and investigates the disappearance of humans and Pokémon. The character meets Ditto early in the story and helps frame the game’s central mystery.

Rather than receiving guidance from a conventional human Pokémon professor, the player encounters a Pokémon who has adopted an academic role. This choice fits Pokopia’s unusual setting, where humans have left the region and Pokémon must rebuild their surroundings themselves.

Professor Oak, Professor Kukui, and Professor Rowan are all genuine Pokémon professors from other games, which makes them plausible distractors. They are not the researcher who accompanies Ditto in Pokémon Pokopia. The full in-game name is Professor Tangrowth, not simply Tangrowth.