I really enjoy everything that you have done with this panel. Each panels progresses the story in a very natural sense, it flows great. I am not familiar with this content so I do not know if it is original or not but it looks great.
As far as the monster goes on the third panel, he does seem to be a little flat. I think there would be a greater impact if his right hand (the hand on the tree) was more in the background and his left hand (grabbing hand) was closer giving a much more dramatic depth. I think the same thing of his left leg, it seems not quite as dynamic as the right leg and looses some of the menacing impact it could have.
Still, much better then I can do. Your placement of the three characters in the lower right of the panel works great as well.