What is Pokédex number 001 in the Pokémon series?

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

The bulb on Bulbasaur's back is planted at birth and grows with it. The species is described as being able to survive for days without eating because the bulb stores energy through photosynthesis. Its evolutionary line continues with Ivysaur and Venusaur.

Bulbasaur is the first entry in the National Pokédex, but it is not the first Pokémon seen in the original animated series. The television series opens with Pikachu as Ash's partner and briefly shows the legendary Ho-Oh, a distinction that often causes confusion between game numbering and anime appearances.

Bulbasaur is also notable for being the first listed member of the original Grass starter line. The other first-generation starter choices are Charmander, a Fire type, and Squirtle, a Water type.