The dragon Fafnir of Norse mythology is a legendary creature that appears in various stories and legends. He was originally a dwarf, but was transformed into a dragon after being cursed by the gods. Fafnir was known for his greed and hoarded a great treasure, which he guarded fiercely. He was eventually slain by the hero Sigurd, who used a magical sword to penetrate Fafnir's armor. Fafnir is often seen as a symbol of greed and avarice, and his story serves as a warning against the dangers of such behavior.