No, it would be better to remove the dragons altogether, because undead creatures are more original. And there are already enough dragons. You could make a neutral dragon-lich of level 8, similar to a phoenix.

You're all being silly :) you've conspired. One thing is originality, another is that in every necropolis castle, in all the parts where they exist, there are skeletal dragons. Hence the conclusion - don't touch them! Let them be weak and frail, but at least they are skeletal and dragons.

Dragon-liches are good! They can make the enemy "cry-cry". Their bite can be even more terrifying than a cyclops' attack in some situations.
And they are also cute :)