Umbreon

is one of the more unique Eeveelutions as it requires more than just candy to evolve.

Evolution
To evolve Eevee into an, it must be added as the player's buddy Pokmon and be walked 10km. While it is still the buddy Pokmon, it has to be evolved during the night to evolve into an. If Eevee is evolved during the day instead, it will evolve into Espeon.

Naming an Eevee "Tamao" and then evolving it makes the Eevee evolve into Espeon. This trick works during any time of the day. You can only evolve an Eevee this way once.

References & External Links

 * pkw: on Azurilland Wiki
 * on Serebii.net