Daniel Murphy, better known as Spud or Danny, is a primary character featured in Irvine Welsh's novels Skagboys, Trainspotting, and Porno. He is also featured in Danny Boyle's film adaptations Trainspotting (1996) and T2 Trainspotting, in both of which he is portrayed by Scottish actor Ewen Bremner.
Danny Murphy was raised in the Leith district of Edinburgh, the son of Colleen and an unnamed man. He befriended Mark Renton while in school, and received his first hit of heroin from him as a young adult. He quickly develops an addiction to the drug and turns to petty theft as one way to earn money for his habit. He is eventually arrested and sentenced to time in Saughton Prison. Following his release he falls back into old habits and is eventually charged with petty theft a second time and sent back to prison.
After being released from prison Spud finds himself broke and lonely, struggling to maintain his on-again/off-again relationship with Alison Lozinska. When word spreads that Michael Forrester has acquired a large amount of heroin, Spud is convinced by Simon Williamson and Francis Begbie to convince Renton to help finance the purchase of the heroin, which they can then sell it for a profit in London. The deal is successful, however Renton steals the profits and flees the city; though he still leaves Spud's share of £4,000 in a locker for him to retrieve before fleeing to Amsterdam.
Nine years later, when Renton returns to Edinburgh he discovers Spud is still addicted to heroin but has been regularly attending group counselling sessions in an attempt to kick the habit. He now feels as though he is a burden on Alison and contemplates suicide so that she might collect on his life insurance policy. When Alison begins working for Simon at his pub, he attempts to persuade her to leave Spud and upon learning of this Spud ends their friendship. During an argument with Simon, Spud reveals that he received his share of the heroin deal from Renton nine years earlier, reigniting Simon's grudge against him. Spud pursues his dream of writing a novel regarding the history of Leith.
In the 1996 film adaptation directed by Danny Boyle, Spud is portrayed by Scottish actor Ewen Bremner. Set in the late 1980s, Murphy is shown to be a member of Renton's group of friends. He is addicted to heroin and regularly commits acts of petty theft to support his habit. Unlike in the novels, in which he dates Alison Lozinska, Danny is in a rocky relationship with Gail Houston. He is seen attending outings with Renton, Simon Williamson, Franco Begbie, and Tommy MacKenzie to pubs and nightclubs. His relationship with Gail largely fizzles out after a messy incident following a drunken night out.
When Renton relapses back into addiction, Spud joins him and Williamson on a crime spree which ends with his and Renton's arrest. As Murphy has prior convictions for theft, he is sentenced to a six month incarceration at Saughton Prison while Mark receives a suspended sentence dependent on his completion of a rehabilitation programme.
Following his release, Danny is broke and lonely. Word spreads to Sick Boy and Franco that Mikey Forrester has acquired a large amount of heroin and is looking to rid himself of it quickly. They ask Spud to help them convince Mark into financing the purchase, so that they might sell it for a profit to an associate of Sick Boy's in London. Renton relents, and Spud accompanies him, Simon, and Begbie to London. After selling the heroin, however, Renton steals the £16,000 and flees the city. Sick Boy and Franco are extraordinarily angry with the betrayal, though Mark leaves £4,000 in a locker for Danny to retrieve.
Spud still hasn't kicked his heroin habit. He is also still romantically involved with Alison.