Eevee is a Normal-type Pokémon. It can evolve into eight different forms, each with its unique typing, strengths, and weaknesses.
In Pokémon GO, you can influence Eevee's evolution using specific nicknames or by walking with it as your buddy Pokémon.
How to evolve Eevee into specific forms:
Rename Eevee to "Rainer" before evolving.
Rename Eevee to "Sparky" before evolving.
Rename Eevee to "Pyro" before evolving.
Make Eevee your buddy and walk 10 kilometers, then evolve during the daytime.
Make Eevee your buddy and walk 10 kilometers, then evolve during the nighttime.
Rename Eevee to "Linnea" and evolve it near a mossy PokéStop.
Rename Eevee to "Rea" and evolve it near an icy PokéStop.
Make Eevee your buddy and earn 2 hearts with it before evolving.
You can also evolve Eevee randomly by using 25 Eevee Candy, with no guarantee of the evolution you'll get