Batman Reptilian

What strikes fear into the hearts of those who terrorize Gotham? It used to be Batman, but something far more frightening stalks the shadows—and it's after Gotham's villains, leaving a trail of carnage through the underworld. Now, with Riddler, Penguin, Two-Face, and many more left bloodied and broken in its wake, Batman opens the case on this mysterious reptilian menace and finds himself vexed by one very important question: What on Earth is it?