Originally posted by Happy:

Both Fenrings & Ulvs should drop Fenris Hair, as well as adding starred variants of both. (I haven't seen Starred Ulvs before so thought it would be worth a mention)

Would also make the resource renewable to go & find at night in the mountains.

There's plenty of Fenris hair to be found in the frost caves; you just need to look around a bit.
Usually it's not only found at pedestals, but also at the tapestries hanging from the walls in some rooms.
If you pick the parts shown to be picked first, jump up, hit with a blunt weapon and quite often the whole tapestry will come down as Fenris hair.

When doing it like that, I was able to farm enough fenris hair for a full armor set as well as all its upgrades from 3 Frost caves. And I still have some left.

So even more hair from drops seems a bit useless to me.

Thorin :)