Pokémon’s first generation included 151 species.
These original species were introduced in the 1996 Game Boy games Pocket Monsters Red, Green, and Blue, with the international releases known as Pokémon Red and Blue. The National Pokédex numbers run from Bulbasaur at 0001 to Mew at 0151.
The list includes familiar starters such as Bulbasaur, Charmander, and Squirtle, as well as Pikachu, the legendary birds, Mewtwo, and the mythical Mew. The first-generation group is strongly associated with the Kanto region.
Players sometimes remember the total as 150 because Mew was not normally obtainable through ordinary gameplay at launch. Mew was nevertheless part of the original 151-species roster. MissingNo., a famous glitch, is not an official species and does not increase the count.