In Pokémon Pokopia, Ditto meets Squirtle after helping it recover from dehydration.
This encounter takes place during the early story, after Ditto has met Professor Tangrowth in the abandoned Kanto region. The dehydrated Squirtle helps establish the game’s restorative premise: Ditto is not simply collecting Pokémon, but responding to environmental problems and helping inhabitants survive.
After this encounter, Ditto is tasked with restoring habitats so the Pokémon population can recover. Habitat restoration becomes the main structure of progression, with new areas, construction projects, and Pokémon relationships opening as the world improves.
Squirtle is a Water-type Pokémon from Generation I. Its appearance in this scene fits the story’s concern with water and environmental damage, while also introducing a familiar species in a setting unlike the traditional Pokémon games.