Amy Madison's History
Early life
Amy was born to Catherine Madison and another Sunnydale resident. Her father never made any money and left her and her mother for another woman when she was twelve. Being brought up by her mother, Amy was subject to constant belittling from her single parent who constantly monitored her weight and would make her drink broth whenever she gained "an ounce." During this time, Amy remained unaware of her mother's magical powers.
Amy was a childhood friend of Willow from junior high. Whenever her mom would go on a "broth kick" (a time during which she would padlock the fridge and eat only broth), Amy would come over to Willow's and they would eat brownies together.
Sunnydale High
Amy was a classmate of Buffy Summers' at Sunnydale High School. She and Buffy met when they both tried out for the cheerleading team. Amy performed poorly in the tryouts, but a series of strange injuries to other candidates moved her up in the standings. Buffy suspected that Amy was a witch who was using her powers to harm the other girls so that she could be a cheerleader to live up to her demanding mother.
The investigation revealed that Amy's mother, Catherine, a very powerful witch, had switched bodies with her some months ago because she wanted to relive her youth. Buffy and the Scoobies succeeded in restoring Amy to her own body via a reversal spell, which prompted Catherine to turn her aggression on her daughter, threatening to put her where "[she] couldn't make trouble again." With Buffy's help, one of Catherine's spells managed to backfire and (unbeknownst to them) trapped Catherine in an old cheerleading trophy. Once again, Amy began to live with her father, who constantly tried to spend time with her due to his feeling guilty from having left Amy and her mother.
The following year, Xander Harris realized that Amy had inherited her mother's powers, becoming a potent (if sometimes ineffective) witch, and blackmailed her into casting a love spell for him after catching her using her powers to neglect her homework. Although it was intended to make Cordelia Chase fall in love with him, the spell backfired instead, causing every woman in Sunnydale except Cordelia to fall for him — including Amy. In a jealous rage, she invoked the goddess Hecate for a spell to turn Buffy into a rat when the two confronted each other for Xander. She was eventually forced by Rupert Giles to undo both of her spells.
Rodent years
As the school year passed, Amy continued to pursue her exploration of the dark arts alongside fellow Sunnydale High students Michael Czajak and Willow, who had practicing witchcraft for a year. Due to the influence of the demon known as Hans and Gretta Strauss, the Mothers Opposed to the Occult organization waged a witch hunt that swept Sunnydale. Amy, Willow, and Buffy were nearly burned at the stake, but Amy escaped by transforming herself into a rat.
This became a problem because Willow did not know how to turn her back. Amy lived as a rat for the next few years, cared for by Willow who kept her in a cage in her room and college dorm.
Amy was very briefly turned human again when Willow cast a "My Will Be Done" spell which allowed her to change things just by saying it. Willow talked to Buffy about how she was not a real witch and unknowingly turned Amy, who was on the bed behind the two of them at that time, back into a human by saying the words "first she's a perfectly normal girl," but before Amy could say anything, Willow said "then poof, she's a rat," turning her back into a rodent.
Human Again
Willow had become a powerful witch over the years and permanently "de-ratted" Amy by simply conjuring up a rat transformation reversal spell. Amy took some time to adjust after life as a rat and was unaware of the amount of time that had progressed. Amy, wanting to avoid explaining her disappearance to her father, went to the Bronze with Willow at Amy's impulsive request.
Despite magic use causing problems with her relationship with Tara, Willow impressed Amy with her magical talents when the two witches created mayhem at the club using their powers. The next morning, she returned to her father.
Following the burn-out from the previous night's magic use, Amy introduced Willow to the warlock and magic dealer Rack who Amy had been in contact with before becoming a rat. The introduction of Rack's brand of magic lead to Willow becoming addicted to black magic. Later, when Willow decided to give up magic, Amy cast a spell on her as a sort of gift, causing her to magically manipulate everything she touched for a while due to be exposed to an unstable burst of magical energy.
Willow complained to Amy that this made her attempts to give up magic even harder. Amy responded by mocking her, implying that she did it as revenge for being trapped as a rat for years. As a result, Willow cut Amy out of her life entirely and made it clear to her that she was no longer welcome in the Summers household.
Having physically transformed into Warren Mears, whom she tortured and flayed in a rage over the death of her girlfriend Tara, Willow sought help from the UC Sunnydale Wicca group Daughters of Gaea and discovered that Amy was a member. Amy explained that she had hit "rock bottom," but was doing much better. However, Amy was in fact responsible for Willow's transformation, the result of a hex placed on her, Penance Malediction. This seemingly random event was actually part of a larger plan orchestrated by Warren, after Amy rescued him from death.
Acolyte of Twilight
Amy was discovered by the United States Army during an expedition to be living sixty feet under the Hellmouth after its collapse with her "boyfriend," a still-skinless Warren Mears. Her first words to an exploratory member were "I'm gonna help you kill her." Amy requested unlimited access to all the government's magical hardware as well as a weapons lab for Warren in exchange for their cooperation. If they succeeded in taking Buffy down, Amy wanted full immunity and release for the both of them.
Amy attacked Buffy at the Slayer Organization command center in Scotland, putting her under a "true love spell," a mystical sleep which only a kiss of true love could undo. Raising an army of kilted zombies to battle the Slayers, Amy dueled Willow mid-air before being stepped on by Buffy's sister Dawn Summers, who at the time was in the form of a giant. As Willow magically probed Amy's whereabouts, she suddenly sensed a trap and was pulled through a portal, only to be "greeted" by a saw-wielding Warren.
As Warren tortured Willow, Amy faced off against Satsu and an awakened Buffy, who managed to channel enough of Willow's magic to defeat a demon which Amy conjured. Having seen her dreamspace while asleep, Buffy took the form of Amy's worst nightmare: her mother. Distracted, Amy failed to notice a grenade thrown at her feet by Satsu, and as Buffy and Satsu charged into the room containing Willow, they saw Amy appear and teleport away with Warren in her arms.
Amy and Warren began working under direct orders from Twilight. Together they constructed a missile, covered in mystical runes and candles, and targeted it at the Scottish citadel where the Slayers resided. Warren and Amy then argued over the failed attack on the castle (with Warren threatening to make a robot Amy "with no mouth").
Amy was again involved in an attack on the Slayers in Rome, summoning a goatman to fight them while Amy herself was scrying from far away. This interrupted Warren's attempt to trick Andrew back to the dark side, which Amy did not think would be successful. Amy magically tracked down the Slayers for Twilight after they fled to Tibet and spied on them for a time in the form of a cat.
When Twilight betrayed her and Warren, they formed a truce with Buffy and the rest and helped fight against his forces. Amy survived the battle, but the destruction of the Seed of Wonder caused her magic to dissipate, resulting in Warren's death.
Magic Town
Following Whistler's release of a magic plague that restored a form of magic to London (as well as the Scooby Gang restoring magic itself in the Deeper Well), Amy was seen gathering bottled magic in the London ghetto of Magic Town. It was part of a plan involving Angel, who had taken it upon himself to guard the residents of London from the transformations caused by Whistler's plague, and she became the new boss of Corky Smallwood's minions after his capture by Angel.
Amy later approached Angel to ask how he had managed to resurrect Giles, wanting to resurrect Warren Mears, whose remains she kept in a jar. Although Angel was willing to accept responsibility for Warren's death and at least consider going along with Amy's request so that she does not attempt something dangerous herself, Amy was actually attempting to provoke him into bringing Willow to confront her so that she could get her revenge. However, her strategy backfired when Angel instead recruited Nadira as an ally, Nadira's innate sympathy with the magic of Magic Town allowing her to turn Amy's borrowed magic back on her, resulting in Amy being transformed back into her rat state.
