Sure, I'll give it a-go!
I'll need a nice screencap of your character (if that's what you're wanting in the sig, if not point me to the art you wanna use) and your IGN. If you need help with the screencap I can meet you in-game and take a few for you.
Then just let know what you're looking for; style, size, possible color scheme.
And if you don't care about any of those things I can just go crazy, try something on my own and see what you think of it when it's done.