This really is a wonderfully gone piece. I'm amazed that it took you so long to make it. You just seem so someone who is so prolific you could get anything done quickly. I will admit that Dad seems to be a lot bigger than Bitey. Of course, they're both muscular. The background's great too.
I would like to see them actually fight. You could make a submission out of that. Of course, I don't think a submission could be that well detailed. I'd love to once again, see the speedpainting. Maybe I already have?