Altman has stated that his initial exit was due to producer Julia Smith demanding he was written out after he opposed a decision to make his character gay.

[1] After Smith's departure, the character made numerous brief or more protracted stints until his onscreen death in February 2015, which was written to coincide with the 30th anniversary of EastEnders.

He was notably responsible for the death of Reg Cox (Johnnie Clayton), who was discovered unconscious in the first scene of the programme in 1985, and revealed in the following episode to have died.

During his time on the show, Nick embarked on multiple feuds with Phil Mitchell (Steve McFadden), Billy Mitchell (Perry Fenwick), Michelle Fowler (Susan Tully), Mark Fowler (David Scarboro/Todd Carty), Lisa Fowler (Lucy Benjamin), Tony Carpenter (Oscar James), Ali Osman (Nedjet Salih), Pete Beale (Peter Dean), Kathy Beale (Gillian Taylforth), Clyde Tavernier (Steven Woodcock), Nigel Bates (Paul Bradley), Den Watts (Leslie Grantham), Eddie Skinner (Richard Vanstone), his father Charlie Cotton (Christopher Hancock) and Ronnie Mitchell (Samantha Womack).

[2] A television critic for The Guardian suggested that, for this reason, the character's dastardly motives were rarely questioned by viewers, as his primary function is that of "an agent of chaos".

The fact that he was dead following an attack was the important issue, and Reg's murder was not intended to be solved, it was only there to tell the audience, from the outset, that Walford was a rough and tough place.

They accused Holland of throwing away a great opportunity and suggested that a murder hunt would provide an array of dramatic possibilities that would captivate the audience.

[7] An EastEnders Revealed documentary chronicling the character's time on the show deemed him a liar, a thief and a murderer who "thrived on the pain and the misery of those near to him".

Holland and Smith wanted to introduce the series in a dramatic fashion, and believed the Reg Cox storyline to be a good starting point, allowing various members of the community to be involved with or comment on the circumstances of the old man's murder.

[7] After a few weeks of the police investigation, prime suspect Nick left the Square after attempting to mug Ethel Skinner (Gretchen Franklin), and in April it was reported that he had been arrested.

Upon his return, he broke into Dr. Harold Legg's (Leonard Fenton) surgery and came across Kathy Beale's (Gillian Taylforth) medical records, discovering she had a child at 14 years old.

Nick appears briefly throughout the next few years and eventually meets his father, Charlie (Christopher Hancock) in October 1987 when they both coincidentally turn up to visit Dot.

"[7] The character's appearance was tailored to suit this unlikable, "nasty" image, with EastEnders series consultant Simon Ashdown commenting; "When he comes on, you know this guy is bad.

"[7] With the help of a fake priest, Nick managed to convince his mother of his newfound faith and then began a slow campaign to control her eating habits and poison her in order to claim her money.

[8] Joe Wallace (Jason Rush) eventually came forward, saying he saw Nick out on the square on the night of Eddie's murder, having escaped his room and climbed down a drain pipe.

[9] Upon her return, Dot explained that Nick had been arrested yet again off-screen for drugs possession, and that Zoe and Ashley had moved away, tired of his criminal acts.

"[7] The first steps towards reconciliation were made in 2006 when Jim Branning (John Bardon) received a phone call from Nick who was in a prison hospital with cancer.

His complex relationship with Dot, his criminal tendencies, and his addiction to heroin, violence, and everything else that's bad have made him one of the show's best-remembered and best-loved villains.

Executive producer Diederick Santer spoke of his excitement at Nick's return, hailing the character as an "EastEnders legend" and "one of the show's best-remembered and best-loved villains".

"[10] June Brown revealed that she had been asking producers to bring Altman back to the soap for six or seven years, as the two of them shared such a good working relationship.

"[7] The actor described other changes to his character since his last appearance, detailing how he had become a plumber, begun dressing more smartly, stopped gelling his hair back and no longer wore an earring.

When Billy's cousin, Phil Mitchell (Steve McFadden), found out about this, he led Nick into the barrel store of The Queen Victoria public house, where he beats him up and ties him to a chair.

A few weeks later, Carol Jackson (Lindsey Coulson) asks Charlie for advice, when he leaves his phone at her house, she answers a call and discovers that Nick is still alive.

Yvonne discovers that Nick cut the brakes of the car but he convinces her to frame Phil by planting the oily rag in his coat pocket.

Dot refuses and tells him to ask Jesus instead, seconds before Nick dies in her arms, in the same location that Reg was discovered thirty years prior.

Stacey, Martin and Kush Kazemi (Davood Ghadami) find Nick's body in the same way Den, Ali and Arthur Fowler (Bill Treacher) found Reg Cox thirty years earlier.

[15] The Guardian columnist Charlie Brooker has denied Nick's villainous characterisation, however, writing: "The man simply isn't menacing; he's half as terrifying as an Argos catalogue.

Whereas [Coronation Street villain] Jez Quigley (Lee Boardman) looked as though he'd enjoy riding an onyx stallion through a field full of groaning, recently-impaled victims before galloping home to bathe in the blood of the fallen, Nick Cotton merely looks like he might, at a push, dispute the price of a dented tin of custard with a supermarket checkout girl while you wait behind him, wondering when he last washed his hair.

"[16] The Times's Fiona McCade satirised the character when Altman appeared on the children's TV show Balamory, advising parents to: "be prepared to cover your little ones' eyes as the bad boy of soap strides into the colourful, fictional paradise, no doubt goosing Miss Hoolie, upsetting PC Plum and making Josie jump.

"[17] John Altman was nominated for "Villain of the Year" at the 2015 British Soap Awards, but lost out to Hollyoaks actor, Jeremy Sheffield, who portrays Patrick Blake.