How do you get Eevee Pokemon LeafGreen?
There is a man in Celadon City. He's in one of the buildings on the same row as the Pokemon Center. Go all the way up to the roof and take the pokeball, it should have Eevee in it. Then get whatever stone you need to evolve it into the Pokemon you want.
If you mean in leafgreen and firered you go to the pokemon day care on four island. And you give them to care about your ditto and your eevee. After a while you go to the man standing beside the house and he gives you an egg. When it hatches you have another eevee. (when you give them a ditto and eevee the eevee can be evolved too... And your eevee can even be a…
Eevee evolves into Umbreon (the pokemon you want) or Espeon when it is evolved in day or nighttime. Unfortunately, since Pokemon Leafgreen lacks an internal clock, you must trade your Eevee to Emerald/Sapphire/Ruby or later and let it evolve at night in order to obtain Umbreon. The daytime refers to the hours of 12:00 AM to 12:00 PM, and the nighttime refers to 12:00 PM to 12:00 AM. Have fun.