Now protected, they have an air of arrogance towards their former enemies.
Along the banks of northern Australia's South Alligator River, scores of crocodiles reaching lengths of up to 4.6 metres (15 feet) stretch their jaws or swim in the river's cloudy-brown waters, sensing little to fear from the occasional passing motorboat.
"They are proud devils," said Garry Lindner, who tracks crocodiles inside Kakadu National Park for Environment Australia, a government agency.
As Lindner steers a small aluminium speed boat around the peering eyes of partly submerged crocodiles along the 95 km (58 mile) long river, a 22-caliber rifle close at hand, he speaks of the need for humans to keep their distance.
Attacks on humans are rare thanks to warning signs inside the park exhorting tourists to stay away from river edges and waterholes, known as billabongs.
Crocodiles are territorial and capable of leaping nearly their full length out of the water to attack prey. They have been known to capsize boats and canoes, says Lindner.
Lindner mostly relocates crocodiles to the dense mangrove swamps in the park's interior that are out of bounds to all but the most intrepid tourists, but he is sometimes forced to kill the animals, usually with a single shot, if they pose an immediate danger.
"If we've got to kill one, we will give the croc to the traditional land owners (Aborigines) who regard the meat, especially the tail, as a delicacy, though some people find it a bit fatty," said Lindner at his base in Jabiru, 3,200 km (1,900 miles) northwest of Sydney.
Word of a Lindner kill spreads quickly among the Aborigines, who are quick to stake their claim for the meat.
However, the massive carcass of a crocodile that killed and nearly devoured a German tourist last year before being shot by Lindner sits untouched in a refrigerator near Lindner's office, where crocodile skulls rest on visitors chairs and are stacked atop files.
"No one wants it," he says.
Glenn Bernard Robless, a tour guide, pleaded guilty in March to making a dangerous omission that caused the death of 23-year-old Isabel von Jordan. He received a three-year suspended sentence. Von Jordan was taken by the 4.6 metre (15 ft) crocodile during a moonlight swim in a billabong.
The freshwater and saltwater crocodiles -- wrongly named since both species are at home in any type water -- have been protected from human predators since the 1960s, allowing their numbers to swell in the park.
Long gone are the likes of European royalty and car loads of young men from the area who killed thousands of crocodiles each year, sometimes chasing them across wetlands guns blazing, often with the blessing of cattle farmers who saw the reptiles as vermin.
But as the crocodile population inside the park recovers to more than 6,000 after decades of protection, fears of attacks on visitors are mounting.
Officials of Kakadu, an 8,000 square-mile (20,700 sq km) reserve, have been forced to declare some of the most popular drawcards no-go zones after crocodiles were sighted on the prowl.
"Everyone wants to see a croc, but not up too close," says Tony Heenan, who runs daily treks through Kakadu's riverways and gorges.
Lindner said five large crocodiles were sighted in popular tourist swimming holes this year. Two were known to venture away from the area and one was removed, leaving two unaccounted for, he said.
"We know they are out there, we're just not sure where," Lindner said.
One of the most popular attractions, "Twin Falls" has been closed since the annual "big wet" ended in May due to crocodile sightings. June typically marks the start to the winter vacation season. Another popular spot, Jim Jim Falls, only opened in mid-June.
But even there, one of the first things day-trekkers encounter is a steel-mesh alligator trap, baited with chicken or pig parts, in hopes of snaring any unwanted reptiles before they reach the pitch-black waters of the popular "plunge pool", eerily absent of all but a few daring bathers.