Naturalist Paul Rosolie decided to let an anaconda coil around him. His aim was to focus attention on the destruction of the Amazon rainforest.
He offered himself to the female snake, but wore a specially designed carbon fibre suit equipped with a breathing system to avoid suffocating. It was also fitted with with cameras and a system to communicate.
The idea was for the snake to swallow him, but when his arm was crushed, and he thought it might break, he asked for help, and the mission was aborted.
His attempt was aired on Sunday on Discovery Channel in the United States.
Here are other daredevils who have attempted life-threatening stunts - not for the faint-hearted.
1. Tiger pounces on man in heart-stopping "attack"
Randy Miller, 45, has trained a 200kg tiger to "attack" him. He reared the animal from birth, and has trained it to leap about 5m into the air and pile-drive him onto the ground in a fake attack.
His predator stunts are so amazing that they landed him a "role" in actor Russell Crowe's blockbuster movie Gladiator. Crowe's face was digitally super-imposed onto Miller's for a famous scene when main character Maximus was attacked by one of Miller's tigers.
2. Alligator decides to show who is boss to wrestler
Alligator wrestler Kenny Cypress was performing in Florida, United States, when the alligator clamped down its teeth on his skull. It took four men to step in to make the reptile release its grip. The wrestler survived.
Usually, an alligator clamps onto its prey and rolls over and over again till it has bitten off a chunk of it.
3. Flirting with a crocodile
Two men were filmed dragging a crocodile in and out of water in Thailand. One of them then put his head daringly into the crocodile's mouth for one or two seconds.
Two professional stunt men teased and taunted a bull towards them, then jumped and evaded the bull in the nick of time. They repeated the stunt for more than a minute in front of a large audience.