What type of mammal or reptile prey on saltwater crocodiles?

Both tigers and leopards are known to kill small subadult crocs with the tiger able to prey on larger crocs than the leopard. Once a croc reaches adult size the only predator it need worry about are other large crocs. It should be noted that naturalists have reported adult crocs killing tigers, leapards and several species of sharks. This is usually accomplished with one crushing bite.Crocs are usually considered adult when they reach the 15' TO 16' range.Animals this size can weigh over a ton