There are two sorts of dragon in fiction, broadly speaking; dumb beasts that screech and have an orc sitting on top of them and eat princesses and ones with interesting senses of humour voiced by such luminaries as Sean Connery and Sir John Hurt. But if a dragon is an intelligent, well spoken and such literate fellow, why would they be running around in the nude and living in damp nasty caves?
What is the difference between a mythical creature and any other invented creature?
This deep philosophical problem is possibly more important to the reader and the author than either might necessary realise. It might govern whether the creature can walk or not, can talk or not or even just survive.