Our first look at Joaquin Phoenix's Joker reveals his origin name
Meet Arthur.

Finally, we can compare Joaquin Phoenix's Joker with Jared Leto's and Heath Ledger's takes on the wildest of DC Comics villains.
But that picture is not exactly… wild.
On Sunday, Todd Phillips , director of the yet-to-be-titled Joker movie, posted a picture of Phoenix on Instagram, with the caption "Arthur". Arthur is presumably the name of the Joker before he became the Joker.
Meet Arthur:
In the comics, there's no definitive backstory for Batman's greatest villain. This origin story is written by Phillips (who directed the Hangover trilogy) with Scott Silver, a co-writer on 2010's The Fighter.
The story will be a character study as well as a cautionary tale of "a man disregarded by society who becomes the ultimate supervillain," according to Deadline.
The cast confirmed so far includes Robert De Niro, Zazie Beetz, Frances Conroy and Marc Maron. There was speculation Alec Baldwin had signed on for a role, but that has since been debunked by the actor himself.
For more, here are some set photos from New York, shared on Twitter by pop culture site Just Jared:
It looks like Joaquin Phoenix has started filming as the Joker for the standalone #Joker movie! https://t.co/0uwG4l34o0
— JustJared.com (@JustJared) September 16, 2018
Warner Bros. is working on another Joker movie starring Jared Leto, who took on the role for 2016's Suicide Squad. That film doesn't have a release date yet.
The yet-to-be-titled Joker movie starring Joaquin Phoenix is set to crash into theatres Oct. 4, 2019.
First published Sept. 16 at 8:05 p.m. PT.
Update, Sept. 17, 5:10 p.m.: Adds information on confirmed cast and set photos.