Lothos, played by Rutger Hauer, is a character in the 1992 film Buffy the Vampire Slayer.
Lothos is a powerful vampire king who has killed slayers for generations. He makes his way to Los Angeles and his acolytes turn several Hemery High School students into vampires until Buffy Summers is finally properly trained by Merrick Jamison-Smythe.
The two battle until she finally gets the upper hand and slays him.