In Hush, Killer Croc is transformed from a man with a skin deformity to a flow blown alligator monster. This change in the status quo as far as I'm aware remains up until Flashpoint.
However the next story arc in the Batman title, Broken City portrays Killer Croc as his classic self, ignoring the events of Hush.
The only explaination for this is that Broken City takes place before the events of Hush.