The very first Big Bad in the series was ancient vampire the Master (and nope, this wasn't a crossover with Doctor Who), the leader of the vampire Order of Aurelius who was entrapped in the Hellmouth below Sunnydale. The only way he could escape from his prison was to open the Hellmouth and bring about the apocalypse. Thankfully, as he was such an easy-going guy, he had no qualms about this, sending him into conflict with the Slayer many times. While Mark Metcalf gives a fun, at times creepy, performance, and the character suitably evokes Count Orlok from classic vampire film Nosferatu, the Master is a somewhat disappointing villain. With a similar problem to Adam, the Master doesn't get a great deal to do, forever waiting in the wings until the Hellmouth opens so he can wriggle up to the surface world. Having said that, the Master does get his time to shine in Season One's finale, Prophecy Girl, where he finally escapes his bounds and faces off against Buffy - even killing her, temporarily. You kill the show's lead character and you're still second-from-bottom - sorry Master, you had some tough competition.
