Tim Friede extracts venom from one of his 15 snakes (YouTube)
A factory worker from Milwaukee has been bitten by deadly snakes more than 100 times in an attempt to immunise himself to their venom and help scientists find a vaccine.
In the past 14 years seven types of snake, including rattlesnakes and black mambas, have sunk their fangs into Tim Friede.
In July, literary journal McSweeney's reports that he was bitten by five deadly snakes in 48 hours.
Usually the venom of a black mamba can kill someone in 20 minutes, but Friede, 45, is hoping that his body's capacity to withstand it might help reduce the number of people killed by snake bites every year.
He keeps 15 snakes in the basement of his home, and injects himself with a diluted venom protein to build immunity from bites.
In the early years of his research he allowed two cobras to bite him at once and went into paralysis, but emerged alive.
"When people see what I do they usually swear or ask me if I'm going to die," he told The Sun.
"I hope through developing my own resistance to poison that some groundwork can be laid to build a vaccine for the 125,000 people who die from snake bites every year.
"The poor of Asia and Africa are the majority of the victims."
Tim said he was first bitten when he was five, by a garter snake, and went on to develop a fascination with reptiles.
Test on Friede show that he has extraordinarily high levels of IgG antibodies, which can neutralise snake venom, in his blood stream.
Tim says there are other positive side effects to regularly injecting himself with snake poison, and that he now rarely succumbs to illness and no longer suffers from the allergies he had as a youth.
Friede is not the first person to inject himself with venom to build immunity.
Steve Ludwin, 43, a rock music front man who once performed the same festivals as Pearl Jam and Nirvana, also claims to have built an immunity to deadly snakebites by regularly injecting himself with their venom.
"It's a Jane Fonda workout for my immune system," he told Fox News. "This is going to be my ninth winter without having a sore throat or a cold. I don't want to use the word supernatural, but it feels weird, like I stumbled over something."
Bill Haast, who ran a roadside 'serpentorium' attraction in Florida, died recently aged 100 after a lifetime injecting himself with snake venom.
Transfusions using his blood helped save the lives of hundreds of snakebite victims.
Every year, approximately 100,000 people die from snakebites, and another 250,000 are permanently disabled.