Eevee - Yenra Picture Wiki
Eevee, the Evolution Pokemon, is a fennec fox known for its unstable genetic code which allows it to change and mutate into different forms depending on its environment: Eeveelution.
As a result of its evolution, Eevee would become better suited to living in its surrounding environment. All of Eevee's evolutions are of unique typing in comparison to each other. In Pokémon Red and Green, the player was able to evolve his or her Eevee into one its first three evolutions (Vaporeon, Jolteon, or Flareon) by the use of an elemental stone (though only one can be obtained at a time).