A man who has spent 15 years drawing an imaginary city whose residents are human excrement who have sex in public, and a woman who changed her name to Spartacus have been nominated for this year's Turner Prize.
Spartacus Chetwynd, Paul Noble, Luke Fowler and Elizabeth Price have all been shortlisted for the controversial art award.
Performance artist Chetwynd, 38, who "lives and works in a nudist colony in south London", changed her name from Lali on her 33rd birthday "to remind people they have a choice in life".
"Like my art, my name change annoys people. The moment it stops annoying people, I will rename myself again," she has said.
She puts on puppet performances with a group of friends and family using her own handmade costumes and sets.
Her work includes An Evening With Jabba The Hutt 2003, in which she recast the villain from Return Of The Jedi as a "Stevie Wonder-type smooth operator".
Noble, 48, from London, has been creating detailed drawings of a fictional city, Nobson Newtown, for the last 15 years.
The inhabitants of the partially-ruined city are living excrement, who, in some scenes, engage in orgies.
His work has been described as a parody of an ideal city.
Fowler, 34, from Glasgow, is shortlisted for his film exploring the life and work of Scottish psychiatrist RD Laing.
Price, 45, from London, is in the running for the contemporary art prize for a trilogy of video installations.
The £40,000 Turner Prize sees £25,000 go to the winner and £5,000 each for the other shortlisted artists.
The prize, established in 1984, is given to a British artist under 50 for an outstanding exhibition or other presentation of their work in the 12 months before April 24 2012.
Tate Britain director Penelope Curtis, who is chair of the jury, said of the shortlist: "They are artists that have brought a kind of slowness of looking, it's not a quick fix.
"None of these works are something that you can get in a few minutes. You have to spend an hour or two to get it, whether it's film, drawing or performance."
The judges said there was a "humanity" running through all the artists' work.
They hailed Noble's art as "a compelling life project" of "incredible, monumental graphite drawings".
His work is an "utterly compelling ongoing narrative" and a "limitless journey of discovery", they said.
The artist takes almost "an omnipresent view" of a "dysfunctional world" in which "people become turds and turds become people".
They described Chetwynd, whose recent exhibition Odd Man Out 2011 took the form of a five-hour play addressing issues of "democracy, the right to vote and the consequences of decision-making", as a "very interesting character" who involves the audience in her work.
"She changed her name in 2007. That seems on the face of it ... a small point.
"But the idea of changing her name to Spartacus ... seems to have liberated her to make this ongoing increasingly diverse form of practice that includes as many people as possible," the judges said.
Fowler, best known for his film portraits of public figures, is said to have an "autobiographical and biographical thread to his work".
Price started to make films four years ago and has a musical background - she co-founded the indie-pop outfit Talulah Gosh.
Judges praised her "powerful body of work over the last three years".
Chetwynd uses a troupe of around 20 friends and family in her performances.
She has drawn on everything from the Incredible Hulk to Conan The Barbarian and re-enacted Michael Jackson's pop video Thriller and the wildlife drama Born Free.
The artist, whose mother is a set designer who won an Oscar for Howards End, is always a participant in her productions, wearing just a bikini for An Evening With Jabba The Hutt.
Her other work includes a week-long performance The Walk To Dover, in which she and her troupe dressed as Victorian street urchins to retrace the steps of Charles Dickens' character David Copperfield.
Odd Man Out addressed issues of democracy and saw participants cast votes.
Depending on what vote they cast, they were catapulted down an inflatable slide to a space littered with charred limbs.
A Tax Haven Run By Women was inspired by "financially independent women" like Dolly Parton and took the form of a game show with two teams competing for a ride to a tax haven.
Noble, whose work includes a hellish Heaven and a utopian Hell has said that he will only make one more work in his Nobson Newtown series.
Price's work includes West Hinder, inspired by the sinking of a ship in 2002 with a cargo of luxury cars, and The Woolworths Choir, which featured degraded footage of girl groups.
Work by the shortlisted artists will go on show at Tate Britain in October and the winner will be announced in December.
Bookmakers Ladbrokes installed Chetwynd as 7-4 favourite to win the prize, followed by Noble at 2-1.
Price is 3-1 and Fowler at 4-1
Speaking at the South Bank Sky Arts Awards, Tracey Emin, who was shortlisted in 1999, said: "I think it's hard work and I think that for any artist that accepts the nomination, there is no such thing as a free nomination.
"I mean I got a lot from it and learned a lot from it but with hindsight I would have done it differently.
"It's hard work, really hard work and people must understand that."