 This surname became official with the publication of the canon comic "Buffy the Vampire Slayer Season 11" #7, in which Buffy calls him by it.The name William Pratt may allude to horror actor Boris Karloff, whose birth name was William Henry Pratt, and can also be understood as the British slang term "prat", describing a person of arrogant stupidity.Spike is one of the youngest recurring vampires on the show, though the evidence of his age is contradictory, as the concept of the character evolved over time.