As with other members of his race, Fafnir's appearance is very similar to a dragon from Eastern mythology. He has an anthropomorphic body with a long neck, white scales, and two large horns on his head. Along with this, Fafnir has grey hair on his head, eyebrows, and beard. He wears a purple robe and a pair of black slippers.
Fafnir behaves like a grumpy old man, often screaming and blaming others. He is quite cheating and deceitful, deceiving Luna Nova for a thousand years to be paid money that he was not truly owed. He believes that magic is an outdated thing that has no place in the modern world, which leads to earn money through modern investments.
Back in the day, Fafnir was known as one of the most brutal dragons. A thousand years ago, Luna Nova Academy asked him for a loan that was sealed in a document written in ancient dragonese. Since no one in Luna Nova could read the dragonese, Fafnir took advantage of it so that the directors would pay them regularly a sum of interests that in fact they did not have to pay, as discovered by Diana.
Given the economic problems that Luna Nova was facing, the teachers became unable to pay the requested interest. Because of this, Fafnir sent several of his robot dragons to take the Sorcerer's Stone as a form of payment.
When some students of Luna Nova entered the Rastavan Ruins with the intention of recovering the Sorcerer's Stone, the majority were captured by their robots while the others arrived by their account until his office. When the teachers arrive in an attempt to renegotiate the debt, Fafnir reveals everything about it as well as their intention to destroy Luna Nova if they do not pay it. However, Diana appears then having deciphered the artifice of Fafnir thanks to that she had learned to read dragonese. After being forced to return the Sorcerer's Stone and cancel the debt, he expresses that Luna Nova is destined to disappear as no one is still interested in magic to which Akko responds saying that someday she will make people get excited about the magic again.
Fafnir appears watching the battle of Akko and Diana against the missile, giving them his Fuel Spirit in similar fashion to the rest of the world.
As a dragon, Fafnir possesses a great longevity, having more than thousand years of age. Despite not demonstrating the common skills of dragons like flying and fire breathing, he was able to exhale a gust of wind through his nose capable of sending everything flying ahead.
- Fafnir is arguably one of the oldest character in the series (the other being Molly McIntyre due to her afflicted with the Curse of Time until she eventually restored to normal by the events of Chamber of Time), as he was already around during tne foundation of Luna Nova.
- Fafnir is a dragon from Norse mythology. In the said myth, Fafnir was once a dwarf before being cursed into a serpentine dragon due to his greed, which drove him to take Andvari's ring and gold for himself.
- For more images related to Fafnir, see the file category: Category:Images of Fafnir.