The demons of the forests and mountains are separate from the race of humans. They emerged in an earlier Creation, made by older gods. The ones that have survived into the age of the current Creation are powerful and strange, but rarely seen. Occasionally, though, the demons grow covetous and lustful. Distrustful of each other, they vent their desires upon humans, who are too weak to resist. When a male demon mates with a female human, the union always results in a child, for a demon's seed is powerful, and the child is always male. These children go by many names, but the most common name, spat out with disgust by husbands and fathers, is Bastard.
I sketched this guy out months ago, but it was only recently that I dusted him off and rendered him up.
If you have the time, please check out the short story I wrote about this character. Link.
Here's a digital sketch of a similar sort of character. I'm planning on doing five of these characters, all half-brothers, as well as the demon who fathered them.