Which character helps Ditto investigate the abandoned world in Pokémon Pokopia?

Professor Tangrowth helps Ditto investigate the abandoned world in Pokémon Pokopia.

Professor Tangrowth is a Tangrowth who has taken responsibility for studying the environment and solving the mystery of why humans and Pokémon disappeared. The character meets Ditto early in the story and gives the rebuilding effort a scientific and investigative purpose.

The name is a playful variation on the professor characters familiar from Pokémon games. Unlike Professor Oak or other human researchers, Professor Tangrowth is itself a Pokémon. That distinction is important because Pokopia’s story takes place after humans have left the region.

Professor Tangrowth works alongside Ditto as habitats are restored. The pair also discover clues left behind by humanity, eventually connecting the damaged environment to the departure of humans and the storage of Pokémon in a large computer system.