From here:

The Japanese title, "Poco a Pokémon", may originate from a combination of poco a poco (Spanish or Italian for "little by little") and Pokémon. Similarly, the name "Pokopia" used in other languages may originate from a combination of Pokémon, copy (in reference to Ditto) and utopia.

If that's true, couldn't they have called it Poko a Pokémon in Spanish? It's called Pokémon Pokopia in that localization like the rest. 🤔