Mudbox brief: The Rock

Lots more work to be done, but I thought I'd share this to show who I have chosen for my new brief: to create a digital sculpt of a head.
I believe 'The Rock' (Dwayne Johnson) would be an interesting person to sculpt because he is incredibly bulky and muscular, thus act as a great way in spurring me on to learn about the human anatomy e.g. muscular and bone structure.

Here are some reference pictures I've used for sculpting so far:

Below is my sculpt so far: