Tom and Oscar were in the sewers looking for the escapee, Waylon Jones, also known as the Killer Croc. (Y/N) was trying to track down Lady Arkham as Alice and Crystal reactivated the old bases from Bruce's video. They hear his Growls echoing off the walls, making them uneasy, but they continue through the sewers walking until he pounces at them.
The two battle the giant reptile, hitting him at the same time to confuse him and make it easier to beat him. After a flurry of punches from both sides, Killer Croc is in a lot of pain and falls down until Tom uses his staff to knock the giant Lizard out cold.
Tom: Holy shit, he's durable as hell.
Oscar: No kidding. Well, we should call Cash. Tell him that Killer Croc is apprehended.
Tom: Right.
The two contact Cash and explain everything to him, telling him to send a squad, as they left the sewers.