WARNING: The following contains spoilers for Harley Quinn #66, by Sam Humphries and Sam Basri, on sale now.

Harley Quinn comics have been known for their fourth wall-breaking antics, namely in how they related to the wider DC Universe. However, in Harley Quinn #66, those references extended beyond comic book characters owned by Warner Bros. The issue's conclusion showcases Harley's geeky backpack, filled with comics and dotted with superhero paraphernalia. While some of these make some sense for the character, one interesting element is a button featuring the emblem of Marvel's Hawkeye.

RELATED: What Nobody Realized About Hawkeye

Harley's backpack contains a copy of her own Year of the Villain tie-in issue, but the outside boasts pins of a Batman symbol and a broken heart. They're joined by a purple-and-white target, seemingly referencing the longtime Avengers.

Randomly homaging another company's character certainly fits the book's irreverent tone. The character, like Batman and Harley herself, also lacks any superpowers. The traditional comic book version of Hawkeye even once lived at a circus, fitting in with the clown themes of The Joker and Harley Quinn.

RELATED: Mortal Kombat 11 Skin Turns Cassie Cage Into Harley Quinn

As funny as that random recognition is, it might also be a bit of a stretch. For one, it could be merely a generic target symbol button. Perhaps the Target brand has purple as its main color in the DC Universe? This is especially true given that, unlike his fellow Avengers, Hawkeye does not have an emblem that's set in stone. The rather obvious purple-and-white target icon was primarily used for the archer's acclaimed 2012-2015 series by Matt Fraction, David Aja, Javier Pulido and others. Hey,it could be a nod to DC's Green Arrow -- he's no stranger to Harley -- except if that were the case the button would be, of course, green.

While the randomness of the Hawkeye homage is slightly funny, a more appropriate Marvel hero might  have been Deadpool. Since the New 52, Harley has been used in a vein more similar to the Merc with a Mouth. Her comics have been heavily compared to his, namely with their focus on pop culture-related humor. Having a button with a Deadpool-esque symbol would also be more recognizable.

Still, given the intentional nature of comic book art, and the obvious meaning and references behind the other buttons, this purple-and-white target is surely meant to represent something. It wouldn't be the first case of DC referencing outside franchises, although it is perhaps the least obvious.

Harley Quinn #66 is available now.

KEEP READING: Did The Flash Just Quote a Green Goblin Meme?