Iceberg Lounge is Penguin's famous club featured in the comic books.
The ringtone on The Riddler's cell phone is the same as the "scene change" music from the 1960s TV series Batman.
In the train station, the words "HA HA HA" are spray painted on an air duct - a possible sign of the Joker
Selina Kyle picks up a whip for the first time... just as her DC Comics' counterpart, Catwoman.
The title of this episode Heavydirtysoul is a reference to Twenty One Pilot's song Heavydirtysoul