By now, Eevee's evolutionary forms in the augmented reality app "Pokémon Go" are no longer a secret. The bushy-tailed creature is one of the most fascinating Pokémon in the franchise because of its capability to evolve into different types. In "Pokémon Go," Eevee can evolve into a fire-, water- or an electric-type Pokémon, but it is speculated that it can also transform into a dark and psychic type with the rumored Generation II update.

According to Slash Gear, a tipster who is familiar with the development plans for "Pokémon Go" shared that a game update will be released in 2017. In addition, it was also mentioned that Eevee can evolve into the dark-type and psychic-type, Umbreon and Espeon, respectively.

Players of "Pokémon Go" have long figured out that renaming Eevee with a specific name can help with its evolution. Giving it the name Pyro, Sparky and Rainer will let it evolve into Flareon, Jolteon and Vaporeon, respectively. This has also been confirmed by Niantic CEO John Hanke at the San Diego Comic Con last month.

As for the Gen II Pokémon, Slash Gear reported that there are two things to consider. One is to let Eevee reach a certain amount of Combat Points (CP). In the original game series, Eevee has to be fed with certain roots or herbs to raise its Friendship Level to help it evolve. In "Pokémon GO's" case, it could be the CP.

It was also speculated that the evolution happens at certain times of the day. Since Umbreon and Espeon are associated with night and day, respectively, their evolution might happen at nighttime and daytime. It was mentioned in the report that Niantic might use a player's GPS coordinates to determine the time of day in the region that the player belongs to.

For now, the Eevee Generation II evolution tricks are purely based on speculation. Niantic has yet to confirm all the rumors, especially about the release of a new game update.