The backdrop is a little strange.
While I don't mind its ambiguity, many of the shapes directly mirror forms of his head and mouth.
The slant and length of strokes definitely add a sense of action.
But perhaps explore alternative ways of rendering and/or arranging them.
Alright, thanks for the feedback. Im thinking I'll go with some nice looking clouds for the background. Right now it's just made in 5 mins, to have something, as I want to focus more on the pterodactyl and the caveman first.
I started drawing him, but I don't have very much experience with humans, and anatomy is really hard. I also can't think of a pose, if this would be alright, or maybe I should try to make it a little more epic somehow, like he's holding his club high in the air, and shouting or something like that. And im not sure how to go with the lightning, this is very rough what I have. But I wanted to ask, is the general highlighting and shadows correct? Im having a hard time understanding it, as I can't find any good references, and im drawing it basically by myself.
EDIT: Well, I redid the pose of the caveman a little and textured it a bit more. Im thinking this is better.