Which Pokémon partners with Ditto as a professor in Pokémon Pokopia?

Tangrowth partners with Ditto as Professor Tangrowth in Pokémon Pokopia.

Professor Tangrowth studies the damaged environment and helps investigate why the world became unsuitable for Pokémon. This character gives the rebuilding adventure a guide and a mystery to pursue beyond the practical work of collecting materials and constructing habitats.

Tangrowth’s plant-like design fits the game’s themes of ecological recovery and habitat restoration. As Ditto improves the land, the professor provides context for the abandoned world and the Pokémon living in it.

Tangrowth should not be confused with a human professor from the main Pokémon games. In Pokopia, the professor is a Pokémon character, and the name is used as a title: Professor Tangrowth. The answer is therefore the species name Tangrowth, not a region or a human researcher.