Flareon
Flareon is a Fire-type Pokemon that resembles an orange rabbit with a cream-colored ruff and tail, as well as a cream-colored tuft of fur on its head. To evolve Eevee into Flareon, you need to use a Fire Stone on it. In "Pokemon LeafGreen Version," you can obtain a Fire Stone by purchasing it from the fourth floor of the Celadon Department Store at a price of 2100 Pokedollars; two Fire Stones are also hidden on Mt. Ember.
Jolteon
Jolteon is an Electric-type Pokemon that resembles a yellow rabbit with spiky fur and a white-colored ruff. To evolve Eevee into Jolteon, you need to use a Thunderstone on it. In "Pokemon LeafGreen," you can obtain a Thunderstone by purchasing it form the fourth floor of the Celadon Department Store at a price of 2100 Pokedollars; you can also find two Thunderstones in the Power Plant on Route 10, one of them hidden near Zapdos' location.
Vaporeon
Vaporeon is a Water-type Pokemon that resembles a light blue seal, with a dark blue crest running up its back and three yellow fins on its head. To evolve Eevee into Vaporeon, you need to use a Water Stone on it. In "Pokemon LeafGreen," you can obtain a Water Stone by purchasing it from the fourth floor of the Celadon Department Store at a price of 2100 Pokedollars; you can also find two Water Stones in the Seafoam Islands, located on Route 20.
Unavailable Evolutions
Espeon is a Psychic-type Pokemon that resembles a purple cat with a red gem on its forehead, while Umbreon is a Dark-type Pokemon that resembles a black fox with yellow circles all over its body. Although both of these Pokemon were introduced in the second generation of "Pokemon" games, evolving Eevee into either of them requires leveling Eevee up with high happiness during either daytime or nighttime. However, "Pokemon LeafGreen" completely lacks a function that keeps track of the time of the day, making it impossible to evolve Eevee into either of these two Pokemon.