This is Gob.
He is from Rave Master volumes 13, 14, and 16.
He is of the Oni race, which is why he has horns.
I COULD NOT FIND A COLORED REFRENCE PICTURE OF HIM ANYWHERE!!! D:<
I could've SWORN he was on the spine of one of the Rave Master books. But I looked though ALL of them, and FOUND NOTHING! x_x I had this really strange feeling that his hair was red-orange, though...
Anyways, he's one of my favorite characters in the series, even if he was never in the Anime, and was only in the manga for about... maybe 50 panels? xD; Whatever. He's cool beans, man.
This was originally pencil shaded, but I decided to color it on Gimp. >_> It looks better in b/w...