With San Diego Comic-Con 2015 now fast approaching, it won't be long until we learn more about Suicide Squad (and possibly see some footage from the film, as well). Then again, with production on Suicide Squad taking place in the busy streets of Toronto, we already know quite a bit about the movie.

Previous set images have revealed quite a few plot details from the film, such as an encounter between Jared Leto's Joker and Margot Robbie's Harley Quinn, a cameo from a prominent DC character, and much, much more. As director David Ayer has already promised, there are still plenty of surprises left for audiences when they finally get to see the film next year.

One of the characters who has already had a heavy presence in all of the set leaks and such is Harley Quinn, who's being played by Margot Robbie (The Wolf of Wall Street). Recently, Robbie got to celebrate her birthday on the set of Suicide Squad, in full costume and all, with a Harley Quinn-themed cake:

Harley's cake - thank you squad! A photo posted by @margotrobbie on

Robbie's caption for the photo reads, "Harley's cake - thank you squad!" Displayed on the cake are a number of recreations of comic book covers featuring Harley Quinn front and center, as well as Harley's logo on the side. The actress seems to have been pretty busy lately with an intensive production schedule, so some downtime is probably welcome.

As many would argue, the key to any cast having good chemistry is them getting along on the set. Fortunately, it looks like the cast and crew of Suicide Squad get along quite well. That might not always result in a great movie, but it can't hurt its chances.

While we have already seen more than plenty of Margot Robbie as Harley Quinn, we still have yet to see what her actual performance will be like. Robbie has previously said, before the movie started filming, that she wasn't sure whether Harley would have an accent or not. As Robbie has already proven, she is more than capable of doing a Brooklyn accent, which isn't too far off from Harley's. Whether or not she does the same here remains to be seen, but with Ayer wanting the actors to dive deep into their roles as the iconic DC villains, it's seeming more and more likely that Robbie will bring a faithful portrayal of Quinn to the big screen.

Batman V Superman: Dawn of Justice will be in theaters on March 25th, 2016; Suicide Squad on August 5th, 2016; Wonder Woman – June 23rd, 2017; Justice League – November 17th, 2017; The Flash – March 23rd, 2018; Aquaman – July 27th, 2018; Shazam – April 5th, 2019; Justice League 2 – June 14th, 2019; Cyborg – April 3rd, 2020; Green Lantern – June 19th, 2020.

Source: Margot Robbie