Dennis Rickman was played by Nigel Harman from 2003 to 2005. he was born in 1978 after a one night stand between Den Watts and Paula Rickman he didn't like being dubbed as a mini den while living on the square.
Dennis, the product of a fling between Paula Rickman and "Dirty" Den Watts in 1974, makes his first appearance is in handcuffs, as he is on day release from prison to attend his mother's funeral. His introduction as a full-time character is marked by a fight with Phil Mitchell, in which he floors Phil with a single punch. This launches a rivalry with Phil which continues when Phil reneged on an agreement to meet Dennis for a fight at Phil's garage by bringing several associates who give Dennis a severe beating. Dennis infuriates Phil by seducing his sister Sam, his wife-to-be Kate (who was a former flame of Dennis's) and his daughter's nanny, Joanne Ryan. The rivalry with Phil is concluded by Dennis's father Den when he returns from Spain. Den and Dennis trick Phil into committing an armed robbery at a local factory. They then abscond with the escape ladder and most of the cash, though Den leaves Phil with a few stolen notes and a gun to incriminate him. The feud brings Dennis closer to his father.
Dennis sees East End ganglord Jack Dalton as a father figure as he worked for him collecting debts, amongst other things, and his prison stint is due to working for Jack. After Dennis's release, Jack orders Phil to kill Dennis after he becomes independent of him. Dennis persuades Phil to kill Jack instead so they can both be free of him. Dennis marches him out into the woods at gunpoint and, following Dalton's admission that he ordered Den's murder in the 1980s, shoots him in the head. Dennis remains friends with Dalton's second-in-command, Andy Hunter, and is left the bookmakers in Andy's will after his death at the hands on Johnny Allen.
Dennis has a passionate fling with Den's adopted daughter Sharon on the eve of Den's return but finds himself rejected when Den replaces him. They resume their affair in secret but Den cannot accept a relationship between his children and plots to split them up. Den taunts Dennis with the insinuation that someone had sexually abused him while he was in a children's home, successfully provoking Dennis into accidentally hitting Sharon. A guilt-ridden Den later apologises and explains his reasons for not wanting his son and daughter together, because he wants both of them in his life and he cannot have that if they are sleeping together. Den then tries to explain to Dennis that his feelings for Sharon are simply misguided due to the abuse he suffered as a child, which leaves Dennis confused and he decides to break up with Sharon in order to have a father-son relationship. Despite Sharon's heartache, the Watts reform their strong bond, including the introduction of Den's new wife Chrissie. Dennis moves in with Zoe Slater but cannot reciprocate her love and Sharon seduces him again. They continue their affair in secret behind Zoe and Den's backs they become sick of sneaking around and they plan to leave on Christmas Day. When they announce that they are in love and going to America together, Zoe, desperate to keep Dennis, announces that she is pregnant. Dennis does not want to be an absent father to the baby, so Sharon leaves without him. He stays with Zoe but refuses to sleep with her. She is desperate to get pregnant for real and resorts to sleeping with Den. Dennis catches them in bed and leaves after informing Chrissie about Den and Zoe.
Dennis and Sharon return as a couple, after several months away and demand to see Den. Dennis sees through Chrissie's story that Den has left her for another woman but drops the matter to spare Sharon's feelings. Dennis and Sharon go on to marry, and following this, they learn that Sam Mitchell had exhumed their father's body from his grave in the cellar of The Queen Victoria public house. Den was murdered by Chrissie after she, Zoe and Sam confronted him about his manipulation of lies regarding the three of them (Den had tricked Sam into selling him The Queen Victoria). Chrissie had also lured Sharon back to overhear Den's confessions so that Den would lose the one person in his life that he truly loved. Den attacked Chrissie and Zoe hit Den with a doorstop to stop him. Den then grabbed Chrissie who delivered a fatal blow, leaving Zoe to believe she had killed him. The three women then buried his body in the basement. Dennis and Sharon bring Chrissie to justice and sell The Queen Victoria back to the Mitchells, apparently concluding the Watts/Mitchell feud.
"We did it"
On Christmas Day 2005, Sharon is admitted to hospital with suspected food poisoning, but finds out she is pregnant, despite the previous belief that she was infertile. They prepare to leave on New Year's Eve to start a new life in the United States. Sharon does not tell Dennis that Johnny has threatened to kill him if they have not gone by midnight, but she confides in Phil, who then uses Dennis as a weapon against Johnny. Phil tells Dennis about Johnny threatening Sharon and also that Johnny had murdered Andy. Although Dennis realises Phil was manipulating him, he takes the bait anyway and beats Johnny to the brink of death. Johnny begs for help as he thinks he will die, so Dennis tosses him a mobile phone and says if he can reach it, he will live. Johnny is able to reach the phone and instead of calling for medical assistance, he contacts a henchman to murder Dennis as revenge for his beating. After cleaning his hands of Johnny's blood, Dennis makes his way towards the Albert Square Gardens where the locals are setting up fireworks, to meet Sharon. As they lock eyes, Dennis is stabbed and collapses, dying in Sharon's arms. His last words are "we did it" in reference to their unborn son who was born six months later and named Dennis in honour of his father. It is later revealed that Dennis was killed by Danny Moon.