I've had this sitting around for a while now, and totally forgot to upload it. (I'm still not 100% sure how to spell this thing's name, so I went with the spelling I see most used by fans.) Anyway, this is "Oorotto" from Pokémon X and Y, a dark-looking Tree Pokémon. Once its official Sugimori art is revealed, it'll be interesting to see how close I was.
Added its English name to the title, Trevenant.