Quote Originally Posted by Seraph522 View Post
It's older than Tolkien; he likely drew heavily upon the story of Fafnir from Norse mythology, a dwarf-turned-dragon that guarded the hoard of Andvari, when creating Smaug, and Beowulf features a hoard-guarding dragon as the final opponent of the eponymous hero. Of course, dragons appear worldwide in mythology, so this is mostly a Western European trait of dragons rather than a universal one, and Tolkien popularized the trope of a treasure-guarding dragon in modern fantasy works.
Interestingly, the First does seem to have an analogy of Fafnir: Gomitt, the S Rank Elite Mark of the Tempest, is a dwarf with a similar backstory. Only, instead of turning into a dragon, he turned into a Davy Jones knock-off.

The only actual "Fafnir" in XIV is a voidsent possessing a dead dragon in Eureka Anemos, and he was specifically designed as a throwback to the notorious monster of the same name in XI (right down to using their abilities from that game).