Buffy the Vampire Slayer star James Marsters has said that his fan-favorite character Spike would not have survived long without some behind-the-scenes tutoring from Giles actor Anthony Head. Marsters played British vampire Spike from the show's second season onwards, and famously was so popular that he was upgraded from a guest star to a full-on regular. James Marsters with Buffy co-stars Alyson Hannigan and Anthony Head in 2003. "In the script they had me say 'bullocks' and it was written by an American, so it was spelled 'bullocks.' And frankly, I think he was the best actor on Buffy, and the best human.