Alyson Hannigan (born: March 24, 1974, Washington, D.C., USA) is an American actress. She is best known for her roles as Willow Rosenberg in the television series Buffy the Vampire Slayer (1997–2003), Lily Aldrin on the CBS sitcom How I Met Your Mother (2005–2014) and Michelle Flaherty in the American Pie film series (1999–2012).
"American Pie" cast photo, 1999. Top row: Tara Reid, Chris Klein, Alyson Hannigan, Thomas Ian Nicholas, Natasha Lyonne, Eugene Levy, Jason Biggs, Shannon Elizabeth. Bottom row: Mena Suvari, Seann William Scott, Eddie Kaye Thomas.