What is the first species listed in the National Pokédex?

Bulbasaur is the first species listed in the National Pokédex.

Bulbasaur carries National Pokédex number 001 and is one of the three starter Pokémon offered in Pokémon Red, Green, Blue, and their remakes. It is a dual Grass- and Poison-type species.

The plant bulb on Bulbasaur’s back is part of its body from birth. According to the Pokédex concept, the bulb grows as Bulbasaur receives energy and eventually supports its evolutions, Ivysaur and Venusaur.

Bulbasaur’s position as number 001 is different from its position in a player’s personal Pokédex, which can depend on the game and region. It is also not the first Pokémon encountered in every game, since early routes commonly feature species such as Pidgey and Rattata.