Rumors say Niantic is gearing up to soon unleash Generation 2 of Pokémon in an upcoming update for Pokémon GO. Trainers will soon get a taste of these powerful and exciting pocket monsters in evolved state so it's best to prepare ahead of their imminent arrival.
According to Game 'N' Guide, one will need the specific Pokémon to evolve, so hunting them down prior to the update is highly recommended, and loads of candies to save up. And below is the Pokémon Generation 2 evolution guide, courtesy of PokémonGOInformer.com:
Crobat
It will only take 100 candies to transform the usual pesky winged Zubat Grobat into Crobat.
Bellossom
From Oddish to Gloom and into Bellossom as the final evolution form, this is likely obtainable with the help of 100 candies. Bellossom though is pretty much like Eevee, meaning coming into the last stage of evolution is somehow determined by chance too.
Politoed
Politoed will evolve from Poliwhirl that in turn was originally a Poliwag. Again, trainers will need to feed the earlier generation 100 candies to get Politoed but be reminded that like Bellossom the former is a chance evolution too.
Slowking
Slowking will come from Slowpoke and will require only 50 candies to evolve.
Steelix
The original form is Onix and to jump into the menacing Steelix build, this Pokémon will likely chew in up to 200 candies.
Hitmontop
Hitmontop will owe its existence to Tyrogue, which will require loads of Hitmonchan and Hitmonlee candies to take on the final second-generation form.
Blissey
Eternally happy and cute but robust Blissey will evolve from Chansey with the use of 100 candies.
Kingdra
Water Pokémon Kingdra will leap from Seadra, a member of the Horsea family. Going through three-stage evolution, Kingdra will want no less than 100 candies.
Scizor
Before evolving, trainers may want to consider that the original form known as Scyther is thought to pack more power. But if the decision is to bump up anyway, only 50 candies will do the trick.
Espeon
Espeon is the next stage for Eevee and to get the final form all it takes will be 25 candies.
Umbreon
Also coming from Eevee, Umbreon will take 25 candies and gladly evolve.
Porygon2
As the name implies, Porygon2 is the step up from Porygon and in Pokémon GO evolution will take place fueled only by 50 candies.