Which Pokémon is number 0001 in the National Pokédex?

Bulbasaur is number 0001 in the National Pokédex.

It is one of the three selectable starter Pokémon in Pokémon Red, Green, and Blue, alongside Charmander and Squirtle. Bulbasaur is classified as a dual Grass- and Poison-type Pokémon and carries a plant bulb on its back from birth.

Bulbasaur’s evolutionary line continues with Ivysaur at number 0002 and Venusaur at number 0003. This makes the first three National Pokédex entries a complete evolutionary family rather than three unrelated species.

The National Pokédex number does not indicate a Pokémon’s strength, release date, or popularity. Pikachu, for example, is the franchise mascot but is number 0025. Mew is number 0151 and closes the original first-generation sequence, so Bulbasaur and Mew bookend the original 151.