We can only see them for a moment, but there's a scene where flying, bug-like creatures are abducting people. The evil insects look a whole lot like Parademons, the military force that mega-villain Darkseid uses to subjugate planets. While they may just be some brand new Kryptonian creature from the Phantom Zone or something, it's led to speculation that the big ugly guy is the DC Cinematic Universe's version of Darkseid, which is DC's version of Marvel's Thanos. (Well, actually, Thanos was originally a riff on DC's Darkseid in the comics and—you know what? Never mind.) Darkseid would be a ridiculously huge thing to drop on the first movie in a series of Justice League movies. Darkseid may have an ugly face, but he's also not a snarling animal, so let's put those rumors to rest.