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
Buffy the Vampire Slayer (season 4) and Alyson Hannigan as nervous witch Willow—proving to be wonderfully expressive silent comedians." In the "New York Daily News", David Bianculli states that the episode is "a true tour de force, and another inventive triumph for this vastly underrated series." Robert Hanks from "The Independent" in the UK writes that ""Buffy the Vampire Slayer", in most weeks the funniest and cleverest programme on TV, reached new heights" with "Hush". Noel Murray in The A.V. Club calls it an "episode unlike any other, with a lusher score and some of the most genuinely disturbing imagery I’ve yet seen on "Buffy"." The