While not originally antagonists, they became ones in 2019 after starting the factory fire which killed Frank Clayton.
Amy Wyatt first appeared in the village of Emmerdale when her car broke down in October 2010. She faked being pregnant by stuffing a spare jumper up her top and flagging down Andy Sugden. Andy quickly realised she was faking her pregnancy but agreed to help her anyway and gave her a lift to the garage. Checking the car over, it was revealed that it would need a complete service and Amy was forced to check into the B&B. Attempting to get a discount price, she lied to Pollard telling him she was a trainee nurse. A suspicious Victoria Sugden questioned her and learnt that she was really sixteen years old, had been in foster care and had run away from home. Having no money, Victoria also tried to help Amy escape from the B&B without paying, but they were both caught by Val. Amy offered to work for the two of them in an attempt to pay them back, but later tried to escape again when the police arrived and informed Eric and Val Pollard that Amy had stolen the car she turned up in from her foster parents. Amy was driven away by her social worker. Amy arrived back in the village shortly afterwards and visited Victoria again after running away. Needing a secret place to stay, Victoria hides Amy in the basement of the B&B. Hearing noises, Val starts to believe the B&B is haunted. When Victoria confronts Amy about the amount of noise she is making, Val overhears them. Amy begs Val to let her stay but Pollard orders her out. Amy arrived back at the B&B the following week as Val and Victoria are unpacking shopping from Val's car. She helped them to unpack and Val took her to cafe where Amy reacted nervously upon seeing a policeman investigating a theft. Later, Val sees Amy waiting at a bus stop. Amy tells Val that she is going back to her Children's Home as her foster parents had split up when the husband had an affair. Val gave Amy money for taxi fare. Later, Val received a phone call from the Children's Home, she was told that Amy had locked herself in the bathroom and was refusing to come out unless Val spoke to her. After being emotionally blackmailed by Victoria, Val went to the Children's Home and Amy let her into the bathroom. Val reluctantly agreed to let Amy stay at the B&B. Val and Eric later decided to adopt Amy and were granted approval.
Kerry arrived a year after Amy, in 2012. While on a night out in Hotten, Kerry witnesses her boyfriend, Chris Fletcher, kissing another girl in a bar. Kerry breaks the pair up and smacks the girl. Kerry starts hitting Chris with her handbag and it's at that moment that the girl, Amy Wyatt realises that Kerry is her mother. After Kerry is thrown out of the club, Amy reveals that she is her daughter. Kerry tries to talk to Amy and she gives her her phone number. Kerry later finds Amy's address on Facebook and she comes to Emmerdale to make amends. However, she meets Val Pollard, who tells her to leave. Kerry thanks Val for her help in raising Amy, but vows to come back and sort things out.
Kerry begins a relationship with Andy Sugden. However, Debbie Dingle begins leaving her kids with Andy and Kerry which Kerry soon becomes annoyed about. One night, Kerry becomes drunk and drops a cigarette on the rug and sets Andy's house on fire, nearly killing herself and baby Jack. She and Jack are saved by Andy, Amy, and Cain Dingle, after Andy's daughter Sarah raises the alarm. Andy nearly attacks Kerry and ends their relationship. After getting into a fight with Debbie in the street over the situation, Kerry goes on holiday for a few weeks.
Kerry returns but is horrified to walk in on Andy and Amy kissing and tells them she is pregnant. However, it is revealed she is lying when she asks a pregnant woman to use a pregnancy stick. Kerry shows it to Andy and he buys her another one but the pregnant woman also urinated in a little cup and Kerry tricks Andy into believing she's pregnant. However, she is not convinced and Andy tells her to have an abortion otherwise he will not support her. Kerry's lies become unravelled when she is involved in a hit and run incident and she is forced to admit that she isn't pregnant after all, resulting in Andy and Amy wanting nothing else to do with her.
In the summer of 2013, Kerry embarked on a romance with Dan Spencer even going as far as to get a tattoo on her foot confessing her love for him. They went on to marry in June 2014 but at their wedding reception, it transpired Kerry was already married to Kev Berry and she was subsequently arrested for bigamy. Amy left the village in 2013 to start a new life.
In September 2016 Kerry had a one-night stand with Ross Barton but immediately regretted it. It wasn't long after that she discovered she was pregnant. Dan was over the moon at the prospect of becoming a father again but unsure as to who the father was Kerry underwent an abortion, leaving Dan devastated.
In March 2019, Kerry travelled to Belfast to find Amy. Kerry tracked Amy down to a rough area of the city and told her she needed to come back to Emmerdale for Kyle. Amy was shocked to learn that Joanie was dead and Kyle was in Cain's care and that Cain was facing murder charges for the "death" of Joe Tate. Kerry tried to persuade Amy to come back to Emmerdale to look after Kyle, however, Amy declared she didn't want to be Kyle's mum then walked away. The following day, Amy tells Kerry she couldn't stop thinking Kyle - she gave him up so he can have better but if he's not getting that then she needs to do something. The villagers are stunned to find Amy in the village and Cain's relatives warn her that she has no legal rights to Kyle, but Amy is determined. Amy is adamant she's going to see Kyle whether Cain likes it or not. Cain's mother, Faith Dingle, soon have Amy arrested for kidnap in means to keep her from snatching away Kyle. However, Eric, who was delighted to have Amy back, stating she was like a daughter to him, helped get her off and she told Cain that if he wanted a fight he'd get one.
In late March, Amy walks up to Cain and Moira at the garage and demands to see Kyle, suggesting it's about time he's told she's his mum. Cain agrees so long as Amy goes about it properly. On 1 April 2019, Amy picks Kyle up with the intent of telling him. She reads him a book about adoption then shows him a picture of her holding him as a baby. With some encouragement from Eric, Amy breaks the news to Kyle to that she's his birth mother. She is delighted when he is okay with it and agrees to spend more time together, giving her a hug. Cain starts to gradually let Kyle spend more and more time with Amy and they grow closer.
Amy and Kerry were responsible for the fire and subsequent explosion that killed Frank Clayton at the sweet factory after destroying the CCTV to cover up stealing charity money from the safe. They refused to confess they were responsible, and let Frank get blamed for stealing the charity money. Frank's daughters, Vanessa and Tracy, found out Kerry and Amy were responsible, however did not say anything due to Amelia Spencer.