Watch : Nicholas Brendon, 'Buffy the Vampire Slayer' Actor, Dead at 54 A beloved member of the Buffy the Vampire Slayer cast has passed away. Nicholas Brendon, best know for his role as Xander Harris in the Sarah Michelle Gellar-starring series, died on March 20 at the age of 54, according to his family. "He passed in his sleep of natural causes," they said in a statement to The Hollywood Reporter. "Most people know Nicky for his work as an actor and for the characters he brought to life over the years." Brendon's family said he was "on medications and treatment to manage his diagnosis," including his struggles with cauda equina syndrome (CES), and was "optimistic about the future at the time of his passing." "In recent years Nicky has found his passion in painting and art. Nicky loved to share his enthusiastic talent with his family, friends and fans," they shared. "He was passionate, sensitive, and endlessly driven to create. Those who truly knew him understood that his art was one of the purest reflections of who he was."