Croc's huge, but somehow the Batman's even bigger. But as he's thinking-

Scales trump fur, every time. Croc barrels forwards, aiming to headbutt the Batman's chest-- if it hits right it'll hurt, maybe crack a rib at worst, but Croc wants him in the water. Not bleeding out in the mud.

It's a very specific sort of revenge that he has on his mind-- it ends with the Batman dead, but only after that kid's dead.