Still little time, but again I'll say a few words:
Love it. This guy is pretty schweet; lots of love went into crafting this guy, making him reasonably different from the in-game Ents and Treants and stuff. I particularly like his back; all those twisty trunks & tree bits. Also his tree-rib-cage & tree-crown-of-thorns; very cool!
I like how he has an interesting look while rooted; almost normal enough to stand in, but cool enough to stand out at the same time.
My complaints would be thus: while it's good you put some (leafy) texture in the mouth to contrast things, aside from that there's literally no 'face'; like, I can see it carved in the wood if I zoom in, but from a distance it's impossible to tell. For whatever reason, Blizzard made sure all there Ents/Treants had very defined, recognizable faces; heck, even the meaningless, mass-summonable Treants the KotG summon do! So lined up with them, this guy becomes even *more* faceless & character-less as a result, whether that was your intention or not. I'd say some face would do him good.
Alternatively, as a sort of weird 'campaign' unit you only see once, it's probably just fine. It just strikes me as quite different from the Blizzard ethos in this thing (not like I'm an Ancient expert or anything).
Still, a great model (& importantly, a great & fitting name! You always had a way with that). Keep on keepin' on!