seems to be a rather specific request.
debating the moraltiy of dragon killing... well its a staple of western fantasy.
In DnD, at least in FR; dragons are pretty much colour coded for morality. if its a chromatic dragon, youare probably better off either running away as fast as you can or shanking it.
Since these guys are bareley capeable of repayign a favor.
For one thing, Dragons are an iconic creature in western mythology so id be surprised if they wouldnt sneak one or two in there. Even OS2 had one.
