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
Becoming (Buffy the Vampire Slayer) Becoming (Buffy the Vampire Slayer) "Becoming" is the season finale of the WB Television Network's second season of the drama television series "Buffy the Vampire Slayer", consisting of the twenty-first and twenty-second episodes. The two episodes were split into two broadcasts; "Part 1" first aired on May 12, 1998 and "Part 2" first aired on May 19, 1998. They were written and directed by series creator Joss Whedon. The narrative features vampire slayer Buffy Summers (Sarah Michelle Gellar) working to prevent Angelus (David Boreanaz) and fellow vampires Drusilla (Juliet Landau) and Spike (James Marsters) from awakening the demon Acathla. Production