Muggers also called Marsh Crocodiles
You can readily make out who the boss is. He just climbs over everyone else and lunges first when lunch is announced.
The crocodiles have such a low metabolic rate and conserve energy in a superb fashion. They need a good meal just twenty times a year. While you see crocodiles mostly lying still and quiet, they are capable of moving pretty fast. And surprisingly they can run too.
These are marsh crocodiles also called muggers.
For an entirely different take on this pit, see this.
This picture happens to be the most interesting picture in Flickr with the tag Croc.
See all the crocodile pictures in this stream.