'Suicide Squad' director, David Ayer, says the Joker's tattoos have a more significant meaning than just body art.
In a recent interview with Yahoo, David Ayer stated that there is more to Jared Leto's version of the Joker than meets the eye, not just from a performance basis, but also his physical design. Since the first image of the new Joker was released, it has been a subject of controversy in the fan community. The famed Clown Prince of Crime has never been depicted covered head-to-toe in prison ink, but it seems that the decision has a far greater meaning from a narrative standpoint. Apparently, each one of his tattoos represents a different part of his past, more importantly, his origin.
Putting each tat under a microscope, they begin to make much more sense if you're aware of his lineage in the comics:
-The collage of "HA HA HA" on his chest and forearm could easily be a reference to 'Batman: The Killing Joke', which showed the Joker emerging from the chemical bath that created him with the same thing adorning the backdrop of the famous splashpage.
-On his right bicep, you can see what appears to be a beak and a wing, possibly a robin representing the day he took down Jason Todd (Robin), which has already been confirmed to have happened in the movie universe.
-The skull with a jester hat on his chest could also be a nod to the 'Killing Joke', where he started out as a stand-up comic who was duped into paying off his debt with the mob by masquerading as the Red Hood, only to meet his inevitable fate that night at Ace Chemicals, emerging once and for all as The Joker.
“The tattoos tell a very specific story. And eventually people will decipher them and understand what’s going on, but obviously they’re contentious, any time you do something new it’s contentious. There’s very specific stories and Easter eggs in those tattoos. It’s putting his history on his body.” -David Ayer