|Portrayed by||Jessie Wallace|
|Spin-off Appearances|| Slaters in Detention |
|First Appearance||18th September 2000|
|Duration||2000–05, 2010–16, 2018–|
|Address||31 Albert Square|
|Date of Birth||14 January 1970|
Kathleen "Kat" Moon (née Slater) arrived in Albert Square in 2000 and she is the daughter of Charlie Slater and Viv Slater Kat is the typical Slater, bad tempered and always says what's on her mind much like her younger cousin Stacey Slater.
One day Kat was small she was sick and she couldn't go to school. Viv was busy, so Kat ended up going to work with Charlie in his cab. Kat sat in the passenger side on a seat made out of pillows and Charlie wrapped her in a blanket and they drove around all day picking' up fares.
They went over the Thames, through the tunnel, singing songs, laughing and talking. After that day Kat tried to pretend she was sick all the time but her Mum Viv got suspicious.
A few years later Kat went out in Charlie's cab again but it wasn't the same. She got bored. Charlie got irritable and they just argued.
When Kat was 15 her mother Viv took Kat's sisters Belinda, Little Mo and Zoe to Ireland on Holiday. Kat didn't want to go so she stayed home with her father Charlie and sister Lynne. She took them in there in a van and one day she drove them into a village and left them in a playground. Val went to a Church to pray.
When Val finished and she came out she was crying and Belinda asked her what was wrong. Val said its all Kat's fault. As there were driving away in the van, Belinda turned and looked back at the church and there was these two people staring at us, watching us go. One of them was hold a little boy which may have been Kat's son Luke Slater, Belinda remembered the name of the village as Red Water.
When Kat’s ‘sister‘, Zoe, planned to leave London to work with their uncle, Harry Slater, in Spain, she shouted down Kat’s objections with ‘You can’t tell me what to do, you ain’t my mother.’, to which Kat replied ‘Yes, I am!‘ The story was revealed that Harry had sexually abused her, getting her pregnant at the age of thirteen. Her father Charlie Slater, Harry’s brother, was unaware of this, assuming that the father was a boy with whom Kat attended school. He and his late wife Viv raised Zoe as their daughter together.The woman Zoe had called her mother was really her grandmother, her ‘dad’ was really her uncle and her grandfather; her 'grandmother' was really her great-grandmother; her ‘sister’ was really her mother, her three other 'sisters' were really her aunts and her cousins, and her ‘uncle’ was really her great-uncle and her father! Zoe fled Albert Square, and Kat, insulted by Harry, attempts suicide but is found in the park by Zoe and is rushed to hospital. Charlie attacked and disowned Harry, and ordered him to leave Albert Square and never return.
One of Kat’s boyfriends was Dr. Anthony Trueman. He was mesmerized by her, and they had a lot of fun, but Kat ditched him when he told her he was falling in love with her. Her daughter, Zoe, later became engaged to Anthony, much to the disapproval of Kat and the rest of the Slater family. Zoe cut all ties with Kat over this. As the wedding approached, Zoe disappeared saying, when she reappeared, that she had needed to get away and think about the serious step she was about to take. She was devastated to find Anthony and Kat were back together, this time in a more serious relationship. Kat realized Anthony’s doctor and ‘posh’ friends looked down on her, and that she and Anthony would never fit together, and they broke up. Kat later discovered she was pregnant with Anthony’s baby. She thought about having an abortion but decided to keep the baby. Unfortunately, she had a miscarriage and was comforted by Alfie Moon. It was very sad for her!
In September 2010 Kat returned to the square with heavily pregnant, although she tried to hide this at first from her husband, Alfie. However, she soon revealed to him that the baby was not his but in fact Michael Moon's baby - Alfie's cousin.
Kat eventually gave birth on the 31st December 2010 - at the same time as Ronnie Mitchell. But their happiness was short lived when Ronnie's baby, James, died and a grieving Ronnie switched the babies, leading Kat to think her newborn baby was dead. Months later, Ronnie admitted her wrong-doing and the Moons were reunited with their son.
In early 2012, Kat left Walford to live with Charlie, as he was very unwell, taking Tommy with her. Alfie was left in charge of the pub, and Roxy was kicked out of her house, so Alfie let Roxy work in the Vic and live with him.
Jean was having another breakdown as Michael had taken all of the Vic's money, £10,000. Kat and Alfie returned to find Jean in the bath.
She confronted Alfie about it, but he denied he has it and that any of it ever happened.
In Summer 2012 Kat began an affair with a mystery east-end local. In December 2012, Alfie discovered Kat's affair was with one of the three Branning brothers. Devastated and furious with Kat, Alfie marched over to the Vic to find out which Branning it was. Kat later revealed she was having an affair with Derek. Alfie ended his relationship with Kat - leading her to spend Christmas at the Brannings with her secret lover, Derek.
Kat was reunited with Alfie after she had the affair in 2012. They then were forced to move out of the Vic by Phil (For Revenge) on Boxing Day, after Alfie jilted Roxy on their wedding day to be with Kat.
On Christmas Day 2013, Kat revealed to Alfie that she was pregnant again. They spent their last day in the Vic with Mo, Charlie and Tommy happily together.
In February Kat sees her cousin Stacey from a bus in London, on her way to visiting Alfie in a Hotel. Over the coming weeks Kat desperately tries to track Stacey down. When she does, she goes to Janine to ask her to drop the charges for accusing Stacey of stabbing her. Janine tells Kat she will drop the charges if she changed her alibi the night Michael Died. In March at Janine's and Alice's trial the truth comes out about Kat lying, so she is forced to do 100 hours of community service. Stacey is sent to prison after confessing she killed Archie. Kat gave birth to twin boys Bert and Ernie on 8th August whilst visiting Jean in Hospital.
She then briefly moved back to the square, while there her dad Charlie died and she became distraught. When the funeral day came Kat was bitter toward her Nan and Belinda arguing with her. When Kat saw Stacey so crazed and wild she decided to stay home form the funeral and aided Stacey, the two and Stacey's son all stay at the pub all day. Kat reminisced about many happy memories with her dad and his taxi, later when Stacey's husband returned back from the church Kat angrly confronted him shouting at him for allowing Stacey to get so mentally unstable. When Belinda and Kat's Nan are about to leave Kat reconciled with Belinda and apologised for her wrongdoing and bitterness to her. A few days later Kat and Alfie left the square.
On the 20th December 2017, it was announced that Kat, portrayed by Jessie Wallace (Wild at Heart, A Class Apart) would return, along with fellow Slater ladies Big Mo and Jean, after seen lifelessly floating in a pool of blood after an altercation with son Dermott in Kat and Alfie: Redwater. No details have been released on upcoming storylines, and fans are speculating over Alfie's fate, as his return has not been announced. Jessie said of her return: "I am thrilled to be returning to EastEnders next year and knowing what John Yorke has in store for the Slaters is incredibly exciting. I love Kat and Walford dearly and I cannot wait to get started – watch out Walford, Kat’s coming home!", with EastEnders executive consultant saying "The Slaters are one of the all-time great families in EastEnders and Albert Square has never felt quite the same since they scattered to different ends of the country, and in some cases beyond." Kat's return storyline is set to be, along with Jean, Mo and the new Slater's, the 'biggest ones in all soap operas of 2018'. It was later revealed that this would be in March or April after news of her "death" reaches the Square.