Hansen, it's a very interesting drawing. I dig the lines and shapes, wonkiness in perspective and grounding included. However the head seems like a passing thought and otherwise ruins a great drawing. I wish I had some more specific advice for you like make the head bigger or increase the mass of the back-cranium, and while those might help, I'm not sure it would without seeing it.
I recommend drawing different heads on post-its and super-imposing them on the drawing till you ifnd one that works.
Of course, that's only my opinion and you're free to disregard completely.
Maester - good stuff!