Coogler did his research. The earliest European stories on vampires come from Irish mythology of the Abhartach that dates back to 450 AD. Bram Stoker, who is also Irish, based his novel Dracula on this Irish legend of a cruel Irish Chieftain that drank blood kept coming back from the dead. But because Dracula was so popular and influential, because he set his novel in Eastern Europe and framed it within real East European history with Vlad The Impaler, people wrong think Vampires come out of East European mythology, when it actually originated from Irish mythology. So Coogler was not only paying tribute to how blues music influenced modern genres of music and how African traditions influenced African American culture, but he was also paying tribute to the Irish origins of vampires. Not only did the Irish have the earliest stories of vampires, they set up all the rules of vampires.