In the PS4, Xbox One, PC and Wii U versions of the game, hovering over most character portraits in the select screen for a few seconds will prompt them to sing the theme song from The 1960s Batman TV show. Superman and Wonder Woman have a similar Easter Egg where they sing the classic theme from their own respective TV shows.
Contributed by KidDivinegon
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In the Hall of Doom, a Weeping Angel from Doctor Who can be found. Every time you move the camera away from it, its hands will move from its face and then cover it back.
Contributed by KnowledgeBase
During the Announcment Trailer, Wonder Woman critisized Batman's Space Suit by saying he "should have stuck with black, or a very dark grey." This is a refrence to Batman's similar line in The Lego Movie.
Contributed by Boyobmas