Mobile smash hit Pokémon Go is being prepped for the second generation of Pokémon species.
That's according to details datamined from the game's latest Android patch, discovered by TheSilphRoad.
v0.45.0 includes the first lines of creature data for Pokémon numbered #152 (Chikorita) through to #251 (Celebi), although their models and move data have yet to be added.
These 100 Pokémon debuted in the second generation of games, Pokémon Gold and Silver, which originally launched for Game Boy Color back in 1999.
This generation introduced cute egg Pokémon Togepi, new starters Cyndaquil, Totodile and Chikorita, as well as baby Pikachu - Pichu.
Pokémon Go even includes placeholders for all of the second generation legendary monsters such as Ho-Oh and Lugia - despite first generation legendaries such as Articuno, Zapdos, Moltres, Mewtwo and Mew not yet being available.
On top of all that, the latest update finally sees the inclusion of Ditto's move Transform. Shape-shifting Ditto is the only non-legendary Pokémon from the original 151 species not currently available to catch in the game. It remains to be seen how it will appear.
Pokémon Go developer Niantic has yet to say when more Pokémon will be added to the game, although it has announced the upcoming addition of daily quests - not yet released, but also spotted in the latest update data.