The Batman: 9 Things That Are Impossible If Ben Affleck Returns
7. Any Good Killer Croc Story
Thanks to Suicide Squad having now happened in the past (since the end of it directly sets up Justice League, what with the files Amanda Waller passes on to Bruce Wayne, there's no opportunity to use any of the villains that formed the Squad in Batman movies. Certainly not in first appearance style stories.
That doesn't so much matter because there's nobody in the entire world who wants to see Batman face off with Slipknot, Captain Boomerang, Enchantress or El Diablo. They're low level for a reason, and they simply wouldn't carry any weight as Batman movie villains.
But that's not quite the case with Killer Croc. He might have been horrifically fudged in Suicide Squad but he's still an incredibly intriguing character - at least in his traditional form, anyway - and there have been some great stories centred on him (Beauty & The Beast and Requiem For A Killer for instance) and it would be legitimately great to see him battle Batman in a genuine monster movie.
Sadly, none of that is possible in this timeline, because he's dead as well as being terrible.