Head of the Moon family, Eddie Moon's bubbly character livens up every room he's in. Although he's a charismatic cockney, Eddie also has a touch of class. As well as being popular with the ladies, Eddie is a polite gentleman and once he makes a friend, he makes them for life.
Due to his past, Eddie is a different man today than he was before. His first love ended tragically when his first wife killed herself. Wracked by guilt and blamed by their son, Michael, he detached himself from the family.
Eddie further estranged himself from Michael as he resolved to become a man who people would be glad to know - someone they would respect and admire - and in doing so started a new family.
Reconnecting with son Michael years later, he fears his dark past will resurface. Can Eddie be the Dad he wants to be despite his kids growing up? And, when his past rears its ugly head, can Eddie preserve his hero status in his children's eyes?
Eddie is first seen reading a newspaper mentioning his second cousin Alfie Moon and decides to visit as he has not seen him for 15 years and wants to see Alfie's son, Tommy, but is hit by Carol Jackson's car outside The Queen Victoria public house. When he comes to, he argues with Carol and Kat Moon asks who he is. At that point, Alfie enters and recognises Eddie. Kat does not want Eddie to stay as she does not want him to know that Michael is Tommy's birth father. Michael sees Eddie in the pub but leaves immediately as he does not want to speak to him. Alfie later tells Eddie that Tommy is his grandson.
The next day, Eddie and Carol talk but he defends his son when she says she thinks Michael has a mean streak. He gives Kat some money for Tommy before leaving but does not go far and bonds with Carol's grandson, Liam Butcher. Kat finds Eddie and invites him to stay. They visit Michael's boxing club where he tells Michael that he should have told him Tommy is his grandson. Michael, however, gives Eddie money and tells him to take his family far away. Eddie asks what it will take for him to get over what happened, and later tells Michael's girlfriend Roxy Mitchell that he does not remember why they fell out. Roxy and Eddie bond and Michael is annoyed. Michael repeatedly tells Eddie to stay away from him, Tommy and Roxy but Kat tells him he can stay for as long as he wants. Michael tells Roxy that Eddie murdered his mother, Maggie. Eddie confirms this but says he was not there when she died but left Michael with her (he was then 6 years old), knowing he shouldn't. She died of an overdose and Michael blames him. He later helps Carol fix a blocked sink at the café and she invites him for tea after he bonds further with Liam. Liam skips school and Eddie helps him with a hobby. Carol is annoyed that Liam did not go to school but thanks Eddie for spending time with Liam by kissing him. Eddie's son, Tyler Moon, arrives in Walford and makes Eddie miss meeting Michael to try to make amends. Michael refuses to accept Eddie's apology.
Eddie sends Kat and Alfie on holiday to Spain and runs the pub in their absence. He teaches Liam about antiques but considers returning to Upton Park as he hasn't seen anywhere to move his business to. When Carol discovers that Eddie has allowed Liam to skip school, they argue and Carol tells him to stay away from her and Liam. Eddie discovers that someone is squatting in a local lock-up and decides to take over the premises. Eddie asks Liam to watch his stock, which he leaves in the gardens. Eddie's son, Anthony Moon, poses as a member of the council to force the squatter out. Eddie returns to find his stock on fire and cannot extinguish the flames. He confronts Michael, thinking he started the fire, but Lola Pearce told Liam that she was responsible in revenge for comments Anthony and Tyler made about her grandfather Billy Mitchell. Eddie finds out it was Lola and confronts her. Eddie and Michael seemingly make amends but Eddie is unaware that Michael has a plan. He later gets a letter that intrigues Jean Slater and she becomes fascinated by Eddie. When she tells him she knows his secret, that he wears silk underwear, Eddie assumes she read the letter and shouts at her. Eddie moves into a house on Albert Square and tells Michael that he likes Carol. They are set up by Eddie's sons to spend time alone and are caught under a blanket by Tyler and Anthony.
When Vanessa Gold is humiliated after Max's affair with his ex-wife, Eddie is kind to her and Michael takes the opportunity to pay Vanessa to break Eddie's heart and she accepts. Eventually, Eddie and Vanessa sleep together but she starts to like him for real. She finds out Tyler is entering an unlicensed boxing match, and tells Eddie. Despite his anger, he supports Tyler after Michael convinces him there will be a proper doctor and referee present. Carol sees Eddie and Vanessa together, and after Tyler wins the fight, he collapses and suffers a seizure. Eddie then finds out that Anthony bet £8000 from the business on Tyler to lose. Eddie tells Anthony he wishes Anthony was the one in hospital instead of Tyler. When Eddie speaks to Michael, Michael blames Eddie for the events because Tyler worships is father. Michael then tells Eddie he knows about Eddie's other child after finding a photograph of Eddie, a woman and a baby with a date of birth on the back, and says that Eddie cheated on his mother, causing her to kill herself. Eddie then speaks to Carol and she rejects him, calling him a monster for cheating with Vanessa. Eddie then promises Michael he will tell him the truth about everything. It transpires that Maggie had hoped Michael would find her and save her life. Michael and Eddie then make amends until Vanessa, with whom Eddie now has a relationship, reveals that Michael paid her to break his heart and arranged Tyler's fight so Tyler would end up hurt. Eddie later reveals this to Tyler and Anthony, who turn against Michael, and Michael is left distraught. Eddie convinces Vanessa to steal cash from Michael, planning to move to Spain with his family. However, Tyler and Anthony refuse to leave and Eddie dumps Vanessa, telling her the police are looking for her. Eddie then collects Craig and they go to Spain to meet Frankie, Eddie's daughter. Several months later, it is mentioned that Eddie has no money. He also refuses to attend Michael's wedding to Janine Butcher in June 2012 or Michael's funeral in November 2013.