8) KGBeast
Instead of Mercy, Lex Luthor’s main henchman in the film is the Russian mercenary who pops up throughout proceedings. He’s there in Africa when Lois Lane is in trouble (plus he later dresses up as a janitor to kidnap her) and he’s responsible for almost killing Martha Kent.
When Bruce Wayne investigates his identity it is revealed that his name is Anatoli Knyazev – the real name of Batman supervillain KGBeast. While they share a name, nationality and profession, the character in the comics is visually very different. Apart from his more colourful costume, he also has a gun for an arm.
Another easily-missed nod comes in the form of Ralli’s Diner, where Martha Kent works before Luthor’s goons kidnap her. This same diner appears in a one-shot comic from 1987, in which Lex gives a waitress a creepy offer: if she comes and stays with him for a month, he’ll give her $1 million. He doesn’t try anything like that with Martha, though.