Nicholas Brendon, best known for portraying Xander Harris on Buffy the Vampire Slayer, has passed away. He was only 54. His family broke the news in an Instagram post on Friday, revealing that he died in his sleep from natural causes. They wrote: "We are heartbroken to share the passing of our brother and son, Nicholas Brendon. He passed in his sleep of natural causes. Most people know Nicky for his work as an actor and for the characters he brought to life over the years. In recent years Nicky has found his passion in painting and art.