He has transformed into the infamous criminal mastermind and Batman's nemesis for his new film.

And Joaquin Phoenix looked positively maniacal as he was hauled away in a police car during filming of Joker in Newark, New Jersey on Monday.

The Oscar-nominated actor, 43, cracked a deranged smile as he sported the villain's signature green hair, white face paint and slit scarlet smile while being hauled away in a Gotham police car.

Eerie: Joaquin Phoenix looked positively maniacal as he was hauled away in a police car during filming of Joker in Newark, New Jersey on Monday

Creepy: A menacing crony of the Joker was seen sporting a creepy clown mask and wielding a baseball bat as filming continued on the hotly anticipated flick

A menacing crony of the Joker was seen sporting a creepy clown mask and wielding a baseball bat as filming continued on the hotly anticipated flick.

Gladiator star Joaquin showed he had mastered the evil Joker's signature laugh as he cackled in the back of the police car as he was driven off.

A stunt double for the actor was spotted on the set, clad in an olive green rollneck jumper, chestnut blazer and matching trousers as they chatted with an armed police officer.

Seeing double: A stunt double for the actor was spotted on the set, clad in an olive green rollneck jumper, chestnut blazer and matching trousers as they chatted with an armed police officer

Laugh: Gladiator star Joaquin showed he had mastered the evil Joker's signature laugh as he cackled in the back of the police car as he was driven off

Mastery: The actor smiled eerily as he was taken from the scene

The Walk The Line star has been spotted filming on the East Coast over the past few weeks.

The Todd Phillips-directed motion picture will also feature notable names including Zazie Beetz, Robert De Niro and Marc Maron.

It tells the tale of The Joker's early years as a failed stand-up comedian in the 1980s, who turns to a life of crime and chaos in Gotham City.

Warner Bros. has teased the film as the tale of 'a man disregarded by society [that's] not only a gritty character study, but also a broader cautionary tale.'

Phoenix is the latest to transform into the iconic villain, with past actors who have played the role in live-action movies and shows including Jack Nicholson, Jared Leto and late stars Heath Ledger, who won an Oscar for his portrayal, and Cesar Romero.

Zach Galifianakis and Mark Hamill have previously provided the voice of the character in animated productions.

The motion picture is slated to come out October 4, 2019.