Amy Thomas (Kate Mansi) was the main villainess of the 2016 Lifetime film Unwanted Guest (airdate August 27, 2016).
Not much is revealed about Amy's past, but it is revealed in the end that she was not originally born as Amy Thomas, as the original Amy Thomas had died two years prior to the movie's events. She was a college student and the roommate of Christine Roberts. Prior to the movie's start, Amy killed student Allen Curwood (who implications say was also Amy's lover) by hitting him over the head before shoving him down an outdoor set of stairs, making it initially appear that his death was accidental.
Later, as Christine prepared to leave for winter break, Amy claimed that her parents were out of the country, causing Christine to invite Amy to her home. Once there, Amy behaved politely with Christine's mother Anna and developed an attraction with her stepfather Charles. Amy showed her first outright sign of villainy that night by giving Christine a glass of drugged wine, and on the next morning, she made breakfast for the family and furthered her flirtations with Charles. Amy fully turned heel later that day, as she returned to the college to murder Allen's girlfriend Marilyn, doing so by going to her dorm room as she was packing her things to leave and bashing her in the head with a wine bottle from the Roberts house. After that, along with sabotaging Anna's real estate work, Amy once again drugged Christine and left the window open before putting on pink lingerie and sharing wine with Charles, becoming more obvious in her seduction attempts. Amy's actions caused Christine to become sick and bedridden, allowing her to further drug her to keep her sick. When a detective investigating Allen's death called, Amy posed as Christine and claimed that Amy was gone. She then went on to kill Mr. Chips (Christine's recently escaped gerbil) by bludgeoning him with a wooden pepper grinder.
While helping Anna prepare for a dinner party for Charles' work, Amy intentionally pushed the stool out from under her as she was reaching for a pot, causing her to break her leg. With both Christine and Anna out of the way, Amy became more aggressive in her pursuit of Charles, eventually leading to a brief affair that Charles immediately regretted. Anna, having grown suspicious of Amy, told Charles about how she felt and was eventually able to convince him to get Amy out of their home somehow. Right before the company dinner party, Amy tried to seduce Charles into kissing her. But he rejected her, upsetting the villainess. Amy also earned the attraction of Charles' co-worker Ken, but after learning that Ken had talked with the detective investigating her, the evil Amy killed him by sabotaging the brakes on his car. The next morning, having found Anna after Amy drugged her food, Charles told Amy that he was hiring a live-in nurse, essentially kicking Amy out. An upset Amy went into a rant against Charles and his family before agreeing to leave.
But as Charles was confronted by the detectives investigating Amy's crimes at work, learning how dangerous Amy truly was, Amy lectured Anna on how she had finally found love with Charles and deserved to have it as she prepared to give her a lethal injection. She was interrupted, however, when Christine called for her from her bedroom. Amy then took Christine out of bed, first saying she was taking her to the hospital before revealing her true self. She and Christine got into a brief fight before Amy was able to forcibly drag Christine into the kitchen, yelling at her about how "ungrateful" she and her family was. She then knocked Christine out with a frying pan and attempted to place her by the open and running stove to die of carbon monoxide poisoning, but this plan failed when Christine awoke in time. As Amy prepared to kill Christine with a knife, Anna ran out from the hallway and injected her with the syringe. Amy shoved Anna down just as the detectives and Charles arrived, and the villainess apologized before collapsing, having succumbed to the drug's deadly effects.
- Kate Mansi portrayed the psychotic Krystal Kellers in the Lifetime film Boyfriend Killer the following year.