Eevee’s National Pokédex number in the Pokémon franchise is 133.
Eevee is a Normal-type Pokémon introduced in the first generation. Its defining feature is its ability to evolve into multiple different Pokémon depending on conditions or items. The original games included Vaporeon, Jolteon, and Flareon as Eevee’s three evolutionary choices.
Later generations expanded Eevee’s possible evolutions with Espeon, Umbreon, Leafeon, Glaceon, and Sylveon. This makes Eevee one of the franchise’s most flexible and recognizable species, but its number remains 133 in the National Pokédex.
Eevee’s number is close to several related entries, which can cause mix-ups. Vaporeon is 134, Jolteon is 135, and Flareon is 136. Pikachu, another famous first-generation species, is 25, so it should not be used as a substitute for Eevee’s entry.