Tangrowth serves as the in-game researcher called Professor Tangrowth in Pokémon Pokopia.
In the story, Professor Tangrowth studies the damaged environment and investigates why humans and Pokémon abandoned the region. The character meets the protagonist, a Ditto imitating a human, and helps guide the effort to restore habitats.
The name is a playful title built from Tangrowth's species name and the academic role of professor. Tangrowth is a Grass-type Pokémon introduced in Generation IV, and its vine-covered appearance fits the game's overgrown, nature-reclaiming setting.
Professor Tangrowth is not the same as Professor Oak, the famous human researcher from the original Kanto games. Nor is the character a new Pokémon species. The title belongs to an existing Pokémon placed into a distinctive narrative role within Pokopia's post-apocalyptic version of Kanto.