Pokemon Evolution

Evolution 

As with original version of Pokémon Go, you can still evolve most of your Pokémon into their later forms by feeding them enough Candy. However, the new Pokémon in Gen 2 introduces 'special' evolution items.

Special items are used to evolve certain creatures and there are five new items that affect how Pokémon evolve:

• King's Rock evolves Poliwhirl into Politoed and Slowpoke into Slowking
• Dragon Scale evolves Seadra into Kingdra
• Sun Stone evolves Gloom into Bellossom and Sunkern into Sunflora
• Up Grade evolves Porygon into Porygon 2
• Metal Coat evolves Onix into Steelix and Scyther into Scizor

For Pokémon with divergent evolutions - such as Gloom or Slowpoke - you'll have the choice of which form to evolve them into. Whichever you choose, you'll still need to spend the requisite amount of Candy to evolve them, along with the appropriate item. They disappear after one use though, so you'll need two King's Rocks to evolve both Poliwhirl and Slowpoke, for instance.

Where to find special Evolution items

Unlike useful items such as Pokémon Lures or Incense, you can't buy the special items in Pokémon Go's store. So where do you get them?

The good news: all five items are random drops from Pokéstops.

The bad news: special items are rare drops. Pokémon eggs have a roughly 20 per cent drop rate, and at present it seems evolution items are even rarer. On top of that, with five different ones necessary and no way to determine which one you'll get, there's a high random factor to getting the one you need. Right now, or until Niantic makes them more easily available, there's no solution aside from persistence.