Joker: Every Easter Egg & Reference We Spotted

16. The Riddler

Though there actually aren't many nods to Batman's wider rogues gallery throughout Joker, there is one kinda-possibly-maybe hint when Arthur visits Arkham State Hospital.

Arthur ends up on an elevator with a restrained patient, and for a brief beat, some graffiti is visible on the elevator wall behind him, which includes a prominent question mark.

Granted, the text itself appears to be nothing more than a generic graffiti tag, but when you put a question mark anywhere near a DC property, fans are immediately going to defer to The Riddler.

Whether intentional or not, it can be read to "confirm" the presence of the supervillain in this world. After all, how many graffiti tags have you ever seen with question marks?

And the fact the tag appears in Arkham State Hospital, where Edward Nygma has likely spent some time, makes it that much more convincing.