The giant saltwater crocodile, the "saltie," is perhaps the most successful predator the world has ever seen. It has survived unchanged for 100 million years. National Geographic uncovers the secrets of this ultimate predator, which has the most powerful jaws since T-rex, the most complex heart in the animal kingdom and a brain with unexpected intelligence. Examine the remarkable features of the croc - from its finely tuned pressure sensors used to detect prey to its lethal predation techniques; from its remarkable pulverizing stomach to its powerful immune system.