The Pokémon Company has shared a special post dedicated to Snom and various other Pokémon:
【公式】雪とハミング
Did you know? It spits out thread imbued with a frigid sort of energy and uses it to tie its body to branches, disguising itself as an icicle while it sleeps. It eats snow that piles up on the ground. The more snow it eats, the bigger and more impressive the spikes on its back grow.
Source: The Pokémon Company
Source:Pokémon