Potential spoilers ahead, so stop reading if you don't want to know anything about the plot of Batman v Superman: Dawn of Justice.
OK, here we go ...
As if Lex Luthor and Doomsday aren't enough, the founders of the Justice League may have another problem to worry about.
Who is Bizarro? Introduced in 1958 in the pages of Superboy #68, he was actually conceived as a hideous duplicate of Superboy/Superman, possessing all his powers but an unstable, almost child-like mentality. That first version of the character was destroyed, but Bizarro came back years later as a Superman clone created by Lex Luthor, ultimately turning against his creator but becoming a regular antagonist for Supes.
From what we've managed to glean from Batman v Superman trailers and online reports, it seems that Lex Luthor (Jesse Eisenberg) uses the DNA of the late General Zod (Michael Shannon) to create Doomsday as an adversary for Superman (Henry Cavill), Batman (Ben Affleck) and Wonder Woman (Gal Gadot). But what if he also gets hold of the DNA of Superman himself and fashions Bizarro out of that? That's one way the movie's narrative could go.
There's no word on how much Bizarro will figure into the action of Batman v Superman -- will he play a major role in the story or simply be set up for the forthcoming Justice League films? A recent tweet from Birth.Movies.Death editor Devin Faraci may provide a clue:
I have learned that BvS added a MAJOR set piece that was not in the script I know. Almost a 4th act.— devin faraci (@devincf) January 12, 2016
For now, keep this all in the "rumor" file, but if Bizarro is indeed going to show up in Batman v Superman when it opens on March 25, do you think this film -- which is also introducing Aquaman (Jason Momoa) and the Flash (Ezra Miller) in addition to Wonder Woman and Doomsday -- is running the risk of becoming way overcrowded?