Some people have tendency to like the photos of living people as their avatar, but obviously for some races some adjustment is required unless you find a really good pic.
this is an avatar for a Chaktawe character I was toying with that I edited to make the eyes look correct, but never used.
here is a picture of the same model, also edited. If you wanted to use either of those for a chaktawe PC you're welcome to them, as they aren't in use anywhere else. Personally, I prefer to draw my PCs because it lets me control every aspect of them... but for Pain, I actually use a blend of my drawings and a model I found that looks damned close.
Really it's up to you, whatever you think represents your character to the rest of Mizahar best is what you should use.
![Smile :)](./images/smilies/smile.gif)