There have been rumours since Justice League's release that Darkseid was initially planned to make an appearance, setting up his larger role in the second Justice League movie, but he was ultimately left out entirely. In his place, we got a shonky CGI Steppenwolf who goes down as one of the worst ever comic book villains, sadly.
In Beall's script, Darkseid would have been restored as the big baddy, with his lieutenant Desaad in tow. And there would have been other villains involved too, with the opening set-piece introducing Desaad in a fight with Killer Croc (which sees Croc bite a shark).
KGBeast is also involved, attempting to sell Kryptonite to Lex Luthor - which Desaad steals - and Amanda Waller makes an appearance as the head of the Department of Metahuman Affairs who seize Killer Croc’s body. And that's not all - there's also appearances by Abel Terrant (Tattooed Man), Copperhead, Barbara Minerva (Cheetah) and Solomon Grundy. So it would have been a busy old affair.