3d modeling: Low Poly Pirate carricature

Today I started character practice of my own. I thought low poly character caricature would be easy enought to do.

Here is my fast sketch & blueprint and my first render. I am having some problems with Blender. in viewport my models are ok (all quads) but in render it makes crazy triangles. Well Im going to find an answer to this problem...

edit: Ok, problem solved! the verticies make the plane little bit twisted so it is normal to have this kind of result with low poly modeling. Edge split modifier fixed this problem!