"I'VE played a lot of monsters," says Christopher Walken.
Anyone who has seen the New York-born actor contemplate suicide in Annie Hall, play Russian roulette in The Deer Hunter, recount the family history of a gold watch in Pulp Fiction, "not kill anybody since 1984" in True Romance, come out of jail in King of New York, or dognap in Seven Psychopaths will recognise the truth of this statement.
But in his newest film, A Late Quartet, the 69-year-old portrays perhaps the most recognisably human character of his career.
"It's true that this guy is a person," he adds in those otherworldly tones that unnerve his on-screen foes and make audiences quiver.
There's no disputing his tough-guy credentials - aged 16 he trained to be a lion-tamer.
His unusual torpid delivery is a reminder of his immigrant background: his father was a baker from Germany, his mother a Scot who never lost her broad accent, and he grew up in Queens in the midst of Middle Eastern families.
In A Late Quartet he plays Peter Mitchell, the elder statesman of a string quartet who, after discovering he has Parkinson's disease, announces that he will perform one final concert.
The news forces the foursome - whose other members are played by Catherine Keener, Philip Seymour Hoffman and Mark Ivanir - to confront the rivalries and disputes that have been bubbling under the surface for years.
The predicament of the cellist seems even more disturbing because of Walken's record of playing demonic, fearless characters.
It's unnerving to see Walken confront his own mortality.
Yet his character in A Late Quartet shares similarities with his villains; Walken specialises in creating a sense of deep-rooted psychological damage, such that even when he has a blank expression on his face, there is something in his empty eyes that is like volcanic molten rock.
There is always method in his madness.
In A Late Quartet, the volcano may be dormant, but the sense of conflicting emotions is palpable.
Walken is also incredibly self-aware, playing on his tough-guy reputation to create self-mocking comic turns.
He was a stalwart on Saturday Night Live, sending up characters he's played on screen and his reputation as a nut.
His seven turns presenting the show are celebrated in a DVD: Christopher Walken: The Best of Saturday Night Live - an honour usually bestowed only on cast members.
He doesn't mind the fact that he's been typecast: "I have a feeling that actors, especially in movies, if they do something that works, there is a chance they are going to repeat something.
"Movies are expensive to make and the people that produce movies want to know what they are getting. I've played a lot of villains, but as I get older it's nice to graduate to play uncles, fathers and grandfathers."
His career started as a child actor under his birth name Ronald Walken.
In 1964 he took his stage name on the suggestion of a singer, Monique van Vooren, with whom he was working at the time.
Walken married the casting director Georgianne Walken (née Thon) in 1969; they have no children, which the actor credits as the reason he has appeared in more than 100 films.
They live together in Connecticut with their cat, Bowtie.
Mystery will always surround the death of his Brainstorm co-star Natalie Wood. Walken was on the boat with her husband, Robert Wagner, when she drowned.
The case was reopened briefly in 2012 and the original "accidental death" verdict was changed to "undetermined death", but the LAPD has stated: "Walken is not a suspect."
Despite working for more than six decades he has no desire to slow down: "I think one of the things about being an actor is that you can keep going as long as you keep going.
"My favourite actor story is about John Gielgud: when he was in his 90s, the Queen Mother, when she was still alive, wanted to throw him a big party, but he had to respectfully decline because he was on location shooting a scene.
"That's what I want, not the queen and the party; I want to be really old and making a movie."
He complains that he recently went to the cinema and was given a senior citizen discount without asking for it: "That hadn't really happened before. They'll ask you sometimes, but she gave it to me automatically and I thought that's it, it's over!"
It's hard to agree, given the number of films Walken has on the horizon. In Stand Up Guys he, Al Pacino and Alan Arkin play old-time gangsters reuniting for one last job; The Power of Few is about an attempt to clone Jesus, and in the contemporary Manhattan-set comedy about the Greek deities Gods Behaving Badly, Walken plays Zeus.
He's also signed up to appear in Errol Morris's 1960s-set cryogenics tale Freezing People is Easy.
"Personally you realise that sticking around is tricky and just to be there year after year, all sorts of things can get in your way," he adds.
"If you are old enough you get forgiven some of your mistakes - the guys look at you and think, he's still swinging and that's appreciated. There is a point where you think I've got to start taking care of myself.
"I have a great constitution and I've taken a lot of beatings and you have to make sure you drink your orange juice and get enough sleep."
He retains his remarkable physique by running every day, using a treadmill to protect a bad back.
As a teenager he trained as a dancer in New York and his career has seen him display memorable dance moves in films including Pennies From Heaven, Hairspray and Search and Destroy.
In 2001 he waltzed his way through the video version of Fat Boy Slim's "Weapon of Choice", which won a Grammy award for Spike Jonze.
His dance prowess led to him getting a call from one of his childhood acting heroes, Marlon Brando.
Brando said he had trained as a dancer and wanted to do a streamed internet music-revue show from his home and asked for the number of the choreographer on Pennies From Heaven.
Brando never called the choreographer but Walken cherished the fact that Brando spoke to him for "a while. I heard later he was a big phone guy."