I found it difficult at first to figure out how to use the mirror modifier and work from a side view especially since the knight is not symmetrical on a side view. The nose and the mane are not mirrors of each other. I did cheat a bit to see how you managed to use the mirror while working from a side view. Of course, after seeing how you set it up, it was perfectly obvious. 
Thanks for again getting me to think a bit outside of the box.
After letting it set for a while, I thought that there were some problems around the mouth area. So, I re-worked it and made some adjustments. This is what I came up with, though still not finished.
