Bryan Singer was hard at work on a sequel to Superman Returns when the studio pulled the plug. Which means we never got to see Brainiac on the big screen, since he was the intended big bad for the sequel. But at least newly revealed concept art gives us a hint at what could have been.
Thanks to Comic Book Movie who discovered this art from illustrator Michael Anthony Jackson, we now know that Brainiac would have looked like an Mars Attacks monster, with a tinge of Darth Vader.
According to a script breakdown from Screenrant, this sequel would have showcased Brainiac traveling from world to world "fixing" each planet (i.e., destroying them). His next target is Earth, and Superman is the only one who can stop him. Also, surprise — it was actually Brainiac who destroyed Krypton. And second surprise — in the epic climax Brainiac downloads his consciousness into Superman's kid. Because HE HAD A KID REMEMBER? LOL, that's terrible. We're glad Singer is sticking to doing what he does best: The X-Men.