I’m sorry, Sage, I don’t really mean it. Normally, you’re bang-on the rules, honestly, and where would we be without your wise assistance to sort through what’s a fairly complicated game? Still, sometimes you come off with rulings that are a little thick.
Apparently, you can get half-dragon dragons - that is, a dragon with draconic ancestry. Buh? While the rules never prohibited the half-dragon template from applying to full-blooded dragons, it’s a ridiculous concept. At best, it could be argued that dragons simply refuse to breed with other colours of dragon as a matter of pride, and that while half-dragon dragons do exist - and are significantly stronger, due to hybrid vigour - they are universally hated by existing dragons and exterminated as a matter of racial purity. I suppose that’s sort of feasible.
Another dumb ruling, related, is the idea that polymorph can be used to apply templates. You would really have to be a rules lawyer to pick this out of the spell description, but as I mentioned in January, it’s technically possible. Of course, no sane DM would allow this under most circumstances, unless he’s fine with his players using a fourth level spell to assume a paragon, half-dragon, half-fiend, werebear version of themselves.