Amy Madison is a fictional character, a witch played by Elizabeth Anne Allen in the television series Buffy the Vampire Slayer. She made appearances in every season of Buffy except Season Five (during which time the character was stuck in the form of a rat due to a spell cast in a previous season). Amy is a witch.
Although initially starting off as a seemingly good-natured individual, Amy gradually grows to misuse her magic, eventually ending up as an enemy to Willow and her friends, becoming a bona fide villain in the series' continuation. Amy is a classmate of Buffy Summers' at Sunnydale High School. Friends with Willow Rosenberg in junior high, she would often go over to Willow's house and eat brownies to escape her mother's abuse.
Amy first appears in the Season One episode "Witch", when she and Buffy both try out for cheerleading. Amy performs poorly in the tryouts, and when a series of strange injuries to other contestants move her up in the standings, the Scooby Gang suspect that she is a witch who is using her powers to harm the other girls. It is revealed that Amy's mother Catherine, a very powerful witch, has switched bodies with Amy because she wants to relive her youth.
Buffy and the Scooby Gang succeed in restoring Amy to her own body and (unknown to them) trapping her mother in an old cheerleading trophy. Amy talks to Buffy after her mother's defeat and mentions that she is now living with her father and step-mother, and that she is much happier.