Pokémon Gold and Silver introduced 100 new Pokémon species to the franchise.
Released in Japan in 1999 for the Game Boy Color, Gold and Silver began Pokémon’s second generation. Their new species ran from Chikorita to Celebi, bringing the total number of Pokémon from 151 to 251.
The games expanded the series with the Johto region, a day-and-night system, Pokémon breeding, held items, and the Dark and Steel types. After completing the Johto adventure, players could also revisit the Kanto region from the original games, making the world feel substantially larger.
The total of 100 new species is separate from the game’s overall Pokédex total of 251. Pokémon Crystal, the enhanced edition, belongs to the same generation but did not add another large group of species. It did introduce story changes, animated battle sprites, a Battle Tower, and the option to play as a female protagonist.