[ZBrush] Rouge Titan sculpt

Sheers

I finished up an organic sculpting class, but I think I can push this character more.  My goal is to make a realistic Rouge Titan and have it as a portfolio piece.  I tried doing the fiber hair, but I'm not so sure about it fitting with him. I did a little posing with the legs for now.  Suggestions on areas to improve would be helpful!

My references are from two places: 
https://www.pinterest.com/einaryoris/anatomy-references-for-artists/
https://www.pinterest.com/sheer2012/anatomy/ 


Thanks!