JOIN USFrom playing-card caricature to diabolical super-villain, the Joker has been reincarnated by a roster of Hollywood stars in his near eight decades on the mean streets of Gotham, with each era painting its own mark on the grinning Batman nemesis.
The chaos-loving prankster, with his clown make-up and rictus grin, first appeared in comic books in 1940 and has made regular appearances on screen since the 1960s.
Most famously played by Jack Nicholson and Heath Ledger, the character has had countless cameos in everything from television commercials to the Scooby-Doo cartoon.
After years as a supporting part, he takes centre stage in "Joker", which premieres Saturday, with Joaquin Phoenix tracing his tortured transformation from victim to villain.
Here's a look at the pop-culture evolution of Gotham's volatile criminal mastermind:
The Joker first appeared to battle Batman in 1940, with slicked green hair, purple suit and a barrage of bad jokes.
US comic book artist Jerry Robinson is widely credited with coming up with the idea for Joker, although Batman creator Bob Kane also said that he and Bill Finger, the original writer on the series, crafted the character.
"Villains, I always thought, were more interesting," Robinson told the New York Times a year before his death in 2011.
"I think the name came first: the Joker. Then I thought of the playing card," he said.
Cesar Romero first brought the Joker to life in a 1960s television series, bringing a gleeful irreverence to a role that was against type for the actor, who had previously been known for playing seducers.
The series was known for its exuberant use of the comic book style, written sound effects for fight scenes, with "POW!" and "ZAP!" projected across the screen as Batman and Robin slugged it out with their criminal foes.
Romero said in 1992 that he preferred the lighthearted, cartoon-type version of "Batman" that he played, describing the popular movie revival as a "dark and dreary crisis drama -- it's anything but 'Batman'".
That 1989 movie version of "Batman", directed by Tim Burton and starred Michael Keaton as the caped crusader, saw Nicholson take the Joker role, in a hammed-up version of the character.
The role was given a more jagged edge in the 2008 film "The Dark Knight", a chillingly sadistic portrayal by Heath Ledger, who won a posthumous Oscar for the role.
Gary Oldman, who played Gotham City police officer Lieutenant Jim Gordon in the film, said he was captivated by the performance.
"Over the years when I've seen great performances -- (Jack) Nicholson in 'One Flew Over the Cuckoo's Nest,' Al Pacino in 'Dog Day Afternoon' -- you go 'wow, there's something really special at work here.' And I think Heath's done that here. It's like he's gone through the sound barrier."
For the latest incarnation, director Todd Phillips has delved deeper into the Joker's past to flesh out his malevolent metamorphosis, drawing on gritty 1970s films such as "Taxi Driver" for the hard-bitten ambience of his "Joker".
"Our hope was to create a character that you really feel for, even root for, up until the point that you just can't anymore," he said.