This is no joke.

Wednesday brought a new trailer for “Joker,” the origin story of Batman’s deranged nemesis, which has revealed that Robert De Niro will appear alongside Joaquin Phoenix, who plays the man who would become “The Joker,” Arthur Fleck, and Zazie Beetz as Fleck’s love interest.

“In a world where everyone thinks they can do my job, check out this guy,” says a smarmy De Niro as the host of a television variety show, reminiscent of his role in Martin Scorsese’s “The King of Comedy.” He then airs a meme of Fleck on stage as a comedian, saying, “When I was a little boy … Everyone laughed at me. Well, no one’s laughing now.”

De Niro’s snarky character replies, “You can say that again, pal.”

Director Todd Phillips (“The Hangover”) seems to be paying homage to Marty, with a shot of Joker in the back of a cab, reminding cinema lovers of the classic Scorsese-De Niro collab “Taxi Driver.” Plus, a line delivered by Batman’s father, Thomas Wayne — “You think this is funny?” — is markedly similar to Joe Pesci’s delivery of the same line in “Goodfellas.”

The new trailer also features comedian and podcaster Marc Maron (“Glow”), who plays a TV producer of De Niro’s sketch show.

“Joker” premieres nationwide on Oct. 4.