Mörkö (Groke in Finnish) used to hunt my childhood nightmares and in some Finnish study she was voted the most frightening character ever. If you've read the books she isn't nearly as scary as in the animated version. Phew, just thinking about that episode gives me the creeps.. But when you think about it she's just lonely. Poor thing.
Anyway, nice work! You captured the feeling very well, I can almost hear her growling. Black woods, a trademark for Groke. If Tino can handle Berwald I'm sure he can manage with this lone wolf as well. (NOT)