Willow Rosenberg was born to Ira and Sheila Rosenberg; she is the only Jewish member of the Scooby Gang. She doesn't appear to have the most superb family life; her parents are out of touch with Willow's life, and her mother once tried to burn her at the stake. Willow has been friends with Xander since childhood (when they were five, they "dated" briefly until Xander stole her Barbie doll), and she quickly became best friends with Buffy when she came to town. Willow is extremely intelligent, a whiz on computers, and an excellent student who is known for her tutoring abilities. She has helped Buffy and Giles numerous times by hacking into various records and databases, and she even taught Jenny Calendar's computer class after Jenny was killed by Angelus. Willow long had "more than friends" feelings toward Xander, and after years of ignoring her, Xander finally seemed to return those feelings — while the two were both dating other people. When Oz and Cordelia found out about their indiscretion, they ended it, and Willow and Oz were able to save their relationship, unlike Xander and Cordelia. Willow will probably always have a soft spot for Xander, as demonstrated by her crying jag when she found out that Xander had slept with Faith. Nonetheless Willow later lost her own virginity to Oz. Willow had a hard time when Oz left Sunnydale, but found love with fellow Wiccan Tara, who in the end she chose over Oz. Willow got increasingly powerful and skilled with magic throughout Season 5, and she was able to hurt and immobilize Glory and restore Tara's sanity (Glory had fed off Tara's mind). In Season 6, Willow continued to further her use of magic, and she and Tara argued about whether Willow overusing it. After Tara found out that Willow had done a spell to make Tara forget their fight, the couple broke up. This, combined with an accident she caused while on a magic high, nearly killing Dawn, provided the catalyst for her giving up magic entirely. A few months later, they got back together, but very shortly thereafter, Tara was tragically shot and killed by Warren. This enraged the powerful witch, and she used dark magicks to make herself extremely powerful, even absorbing the power of the visiting Giles. She killed Warren, then, overwhelmed, decided to end the world. After fighting off Buffy, it was Xander who got through to Willow. Willow went to England for the summer with Giles, who, along with a coven of witches, trained her so that she could control and use properly the magic within her.
    (The Watcher's Guide was used as a reference for seasons one and two.)

Alyson Lee Hannigan, 50, got her start in show business at four years old, modeling and appearing in commercials (for such companies as McDonald's, Six Flags Amusement Parks, and Oreo cookies). At some point, her family moved to Atlanta, and later to California, so that Alyson could audition for more roles. At fourteen, she got her first big role, in the film, My Stepmother is an Alien; interestingly, Seth Green played her love interest in the movie. Though she continued working, Alyson didn't get famous until she got the part of Willow on Buffy, and the recognition has allowed her to start getting bigger roles in bigger movies. Alyson enjoys soccer (she hasn't played too much since she was injured at thirteen, though), she is a fan of old Shirley Temple movies, and she loves dolphins. She is computer literate, though not so much as her BtVS character, and she has been known to check out some of the fan sites dedicated to her and even to post at the official site's posting board. Also of interest: a "Missouri pop punk band" called the Klopecs wrote a song about Aly, which you can check out at their official site (click on Multimedia, click on Lyrics, and choose Alyson Hannigan).

Alyson has been a regular since the beginning, appearing in every episode thus far.