The great Anthony Stewart Head, who passed away at 72, was known to fans of "Buffy the Vampire Slayer" as Buffy's Watcher and mentor figure, Rupert Giles, and he almost got to embark on his own adventures in a spin-off series. Head first appeared as Giles on the very first episode of "Buffy," "Welcome to the Hellmouth," in 1997. He was introduced as both the librarian at Buffy Summers' school and the Watcher assigned to oversee her training as a Slayer.