Snom is a new Pokémon in Sword and Shield. They can evolve into Frosmoth, although there is a little bit of work involved. First, you will need to find Snom.
Snom is a rare spawn and can be found at Steamdrift Way on Route 8, or on Route 10. On Route 8, it will spawn in the overworld, so this is by far the easier place to find it. On Route 10, it will be a hidden encounter, so you will be chasing exclamation marks to try and find it.
Snom’s evolution is unusual because the Pokémon’s level doesn’t matter. Instead, Snom needs to be happy to evolve. You will need Snom to hit 220 Happiness Points for it to evolve into Frosmoth. To increase a Pokémon’s Happiness Points, you will need to have it in your party and win battles with it. Playing with Snom in the Pokémon Camp will also help, as will feeding it plenty of Curry.
As soon as Snom hits 220 Happiness Points, all you need to is wait until nighttime, then level the Pokémon once, and it will evolve into Frosmoth.
If you need more help with Pokémon Sword and Shield, we have a range of guides that you might find useful. From how to use the PC Box Link, how to change a Pokemon’s nature, and how to trade Pokémon. If you are looking for some of the rarer Pokémon, we can show you where to find Dreepy and Ditto, as well.