But despite their size and strength, there are animals that do prey on them. Man appears to be their biggest predator. Big cats like leopards and panthers sometimes kill and eat these big reptiles. Large snakes can also do a lot of damage to alligators and crocodiles.
A hippo would win a fight against a crocodile. Although crocodiles are large, powerful creatures, they cannot kill a fully grown hippo. Hippos are large, roundish animals that are much taller than crocodiles. The only place they would be vulnerable to attack is their legs.
Although adult crocodiles have no natural predators other than humans, hatchlings have a high mortality rate and are preyed upon by other wildlife including raccoons, birds, and crabs.
Once hunted intensively for their hides, today, loss of habitat to human development, illegal killing and roadkill are the greatest threats faced by alligators and crocodiles. As sea level rises due to climate change, a significant portion of freshwater habitats may face saltwater incursion or inundation.
An average crocodile that weighs 700 pounds and measures over 10 feet long is going to be too powerful for a human to overcome.
But how quickly can they run? Most crocodiles can achieve speeds of around 12 to 14 kph for short periods, which is somewhat slower than a fit human can run. Don't believe the hype - if you're reasonably fit, you can definitely outrun a crocodile!
Young crocodiles are often eaten by goannas, birds, fish, other crocodiles, and feral pigs. Mature crocodiles will compete for territory and often fight to the death.
A great white shark would win a fight against a saltwater crocodile. These deadly creatures are incredibly powerful, but the great white shark has an amazing advantage in the water. Not only would this animal probably notice the crocodile first, but it also has the speed to land a devastating attack.
"If they've got hold of you, poking the eyes is the only possible way you can fight back - they have thousands of years of instinct telling them this is the only vulnerable part of their body and they need to let go," Mr Cooper says.
If the fight were to happen on land, a rhino might have the upper hand against a saltwater croc because it is more used to living on land. However, if a fight started close to the water or in the water directly, the crocodile would likely defeat the rhino.
Although confrontations between lions and crocodiles are said to be rare events, incidents of crocodiles attacking lions, and vice versa, have been captured on film before - though the big cats usually shy away from confronting them.
A crocodile would beat an anaconda in a fight. A fully grown crocodile is simply too big and strong for an anaconda to kill. Even in an ambush situation, the anaconda would struggle to wrap enough of its body around the crocodile to inhibit its movement and crush it.
A snake has won a lengthy battle with a crocodile in northern Queensland, wrestling it, constricting it and then finally eating it.
A fully grown saltwater crocodile would win a fight against the largest bears. Size matters in these fights and crocodiles have that advantage. Bears are undoubtedly strong, but they've never faced anything like a crocodile to know their weaknesses.
Tiger Shark vs Crocodile: Final battle
Tiger sharks beat crocodiles in a fight 9 times out of 10. In a final battle between a tiger shark and a crocodile, a tiger shark would almost always kill a crocodile. Tiger shark wins 9 times out of 10.
Elephants, especially bears, are among the large animals that tigers are terrified of. To escape from them, tigers frequently climb trees. A crocodile's razor-sharp jaw might even kill a tiger.
In 2014, an olive python was video-recorded killing and eating a freshwater crocodile at Lake Moondarra, which is near Mount Isa. In that case, it took five hours for the snake to slowly stretch its jaws around the constricted croc. Pythons are able to perform amazing feats of swallowing thanks to their elastic jaws.
Australia's saltwater crocodile has beaten contenders from the US and South America to be named the world's most aggressive crocodile, as new guidelines are released on how to avoid altercations with the formidable predators.
Do Australians eat crocodile? Yes, they do, this unusual meat isn't just a tourist gimmick. You'll see crocodile meat for sale sometimes, and sometimes crocodile sausages, pies, spring rolls, even smoked crocodile.
If a crocodile heads your way, run away in a straight line. The myth about moving in a zig-zag motion is just that—a myth. Crocodiles can move at 10 miles per hour, so remove those flip flops so you can run faster.
"Saltwater crocs have the strongest recorded bite force of any animal on the planet — [the] kind of force can easily crush a human skull," Frost said.
Crocodiles cannot bite underwater
They have a palatal valve that seals off the back of the mouth/throat, preventing water entering the lungs when underwater.