>>45491170In mythos, fairy creatures are not always these kind, gentle, fluttery and cute creatures. Some were considered mischievous at best and malicious at worst.
Goblins for example are often considered a type of fairy.
Hence Grimmsnarl line, I suppose. Point is, a pokemon doesn't need to be cute and cuddly to be a fairy. It needs to hold some sort of magical whimsy, as vague as that is.