Alyson Hannigan 1989, her first regular role on a TV series came when she was cast in the short-lived ABC sitcom "Free Spirit". As a teenager, Hannigan babysat for the children of her future "How I Met Your Mother" costar, Bob Saget. In 1997, Hannigan was cast to play Willow Rosenberg, Buffy Summers' best friend, on the television series "Buffy the Vampire Slayer". The show became a success, and Hannigan gained recognition, subsequently appearing in several films aimed at teenaged audiences, including "American Pie" (1999), "Boys and Girls" (2000), "American Pie 2" (2001), and "American Wedding" (2003). She also had a guest
Watcher (Buffy the Vampire Slayer) Watcher (Buffy the Vampire Slayer) In the fictional Buffyverse established by the television series "Buffy the Vampire Slayer" and "Angel", a Watcher is a member of a secret organization, the Watchers' Council, which seeks to prepare the Slayer to fight demonic forces. A notable example of a Watcher is "Buffy" main character Rupert Giles. Watchers are devoted to tracking and combating malevolent supernatural entities (particularly vampires), primarily by locating individuals with the talents required to fight such beings and win. More specifically, Watchers are assigned to Slayers, girls that are part of a succession of mystically powered individuals who are