It's a staple of Medieval Fantasy that whenever a hero does something noteworthy, they get a "surname" (more properly termed an epithet or byname) out of it, like say Sir Tropesalot, Dragon Slayer. Occasionally, it even sticks as a surname and informs the history of an entire heroic legacy. Eventually, the mere act of saying their full name constitutes a Badass Boast in and of itself — or Famed [...] [tvtropes.org]