Which Pokémon serves as the player’s main research companion in Pokémon Pokopia?

Professor Tangrowth serves as the player’s main research companion in Pokémon Pokopia.

Ditto encounters Tangrowth after finding its trainer’s old Pokédex and taking on a human form. This Tangrowth calls itself Professor Tangrowth and has made it a personal mission to study the damaged environment and investigate why humans and Pokémon disappeared.

Professor Tangrowth helps frame Pokopia’s story as an environmental mystery rather than a conventional Pokémon journey. Together, Tangrowth and Ditto explore the abandoned landscape, restore habitats, and uncover records left behind by humanity.

The name is not the same as the names of other unusual Pokémon encountered in the game. Peakychu is a Pikachu who cannot generate electricity, Smearguru is a talented Smeargle painter, and Mosslax is a plant-covered Snorlax. Professor Tangrowth is specifically the researcher and early story companion.