That being said, it’s certainly unexpected (and pleasantly so) that The LEGO Batman Movie has dug so deep into the DC mythos for its ensemble.
In addition to the inclusion of characters from the Batman mythos, the poster also shows plenty of heroes and villains who exist within the greater DC universe.
In particular, it’s worth noting that major Justice League heroes like Martian Manhunter, The Flash, Aquaman, and Hawkman (to name a few) are all present in the background.