3.The numbers on the armored trucks outside the prison all relate to original Suicide Squad comics that John Ostrander wrote, namely Suicide Squad Issue #5 and Issue #12.
4.In 2016's Suicide Squad, Harley wore a jacket that said "Property of the Joker," and now her jacket reads, "Live Fast Die Clown," which just shows Harley's character arc and her getting over the Joker.
5.When Amanda Waller's team is looking through the Task Force X files, you can spot that Savant was also imprisoned in Iron Heights, an iconic DC comics prison, which is notably seen in The Flash TV series.
6.When Bloodsport is cleaning the bathrooms at Belle Reve, he pulls out a clump of Savant's hair from a shower drain.
7.Amanda Waller mentions that Bloodsport is in prison because he shot Superman with a Kryptonite bullet, which is a storyline pulled directly from DuBois's DC comic debut. In Superman Vol. 2 Issue #4, Lex Luthor enlists DuBois to help him take down Superman by shooting him.
8.The moment when King Shark is reading in his cell in Belle Reve is taken directly from the 2013 comic Suicide SquadIssue #12, where King Shark is reading The Essential Rumi.
9.In Ratcatcher 2's cell, you can see that she has drawings of rats on the walls, but also a photo with her father.
10.While a dozen rats were used to portray Sebastian, one of the rats was named "Crisp Ratt," a play on Chris Pratt's name. Of course, Chris starred in Guardians of the Galaxy, which was also written and directed by James Gunn.
11.While they don't have a lot of screen time, several big DC comics villains make appearances at Belle Reve, including Kaleidoscope, Calendar Man, and Double Down.
12.Of course, the Suicide Squad is tasked with going to Corto Maltese, which is a place that is well-known in DC comics and was first mentioned in Batman: The Dark Knight Returns comic books.
13.The Suicide Squad's mission to infiltrate Jotunheim is a plotline taken from Suicide Squad Issue #1, aka John Ostrander's first Suicide Squad comic.
14.A lot of Harley's tattoos have changed since the 2016 Suicide Squad. For one, she no longer has the "rotten" tattoo on her face.
15.Also, the tattoo on Harley's back now says, "Property of No One," whereas in 2016's Suicide Squad it said, "Property of Joker."
16.Also, while Harley's had this tattoo in every movie, I just love pointing out that the tattoo on her forearm is a nod to Harley's iconic red, white, and black outfit from the comic books.
17.Rick Flag wearing a yellow shirt is a nod to Rick's signature comic book look, which included a bright yellow shirt.
18.Polka Dot Man mentions how his mom worked at S.T.A.R. Labs and experimented on him. Of course, S.T.A.R. Labs is an important lab in DC comics. It's where Victor became Cyborg in Justice League, and it's the main setting in The Flash TV show.
19.Amanda Waller practices golf in her office and mentions she's going to play with Senator Cray. In the comics, Senator Cray is a corrupt politician whose son eventually takes over the mantle of The Atom. Also, Cray was on Oliver's list in Arrow.
20.Not so much a hidden detail, but the movie features cameos from several actors in Guardians of the Galaxy, one of James Gunn's most notable franchises.
21.Lloyd Kaufman, the cofounder of Troma Studios and the director of TheToxic Avenger, can be seen dancing during the club scene. Lloyd notably gave James Gunn his start in film, so he's had cameos in his movies.
22.Rick Flag gives Ratcatcher 2 the nickname "Ratatouille" while they are trying to rescue Harley Quinn, which is, of course, a reference to the Pixar movie Ratatouille and Remy.
23.Harley mentions her hatred for personalized license plates, which is a perfect nod to the Joker's license plate — which read "HAHAHA" — in 2016's Suicide Squad.
24.The Thinker eventually reveals that the monster is named "Starro the Conqueror," which is another thing that was taken from the comics. The monster first appeared in The Brave and the BoldIssue #25, which also marked the first appearance of Rick Flag and the Suicide Squad.