Done Purely on the computer... I used the circle select, the paths tool, multiple layers, the undo and erase tools, lots of patience and going back over it...
Eventually I got this one...

I don't even know... I mean you saw my sketch-to-digital submissions the other day. I used gimp and a MOUSE on a LAPTOP..... The biggest challenge I honestly had was the mane and tail.. and I'm still amazed it came out this nice.. (I know it's not pro.. that's not what I mean. Anything else I'd tried drawing looked like a huge mess...)