893.35 quadrillion to one. That’s the likelihood of what’s happened to 20-year-old Dylan McWilliams. He was bitten by a shark, attacked by a bear, and bitten by a rattlesnake—all in just over three years.

Last week, McWilliams of Grand Junction in western Colorado was body boarding off the island of Kauai, Hawaii, when he felt something hit his leg. "I saw the shark underneath me. I started kicking at it—I know I hit it at least once—and swam to shore as quickly as I could,” McWilliams told the BBC. The wound required seven stitches and the teeth marks suggested it was a tiger shark.

Shark attacks do occasionally happen in Hawaii, especially by tiger sharks, said George Burgess, director emeritus of the Florida Program for Shark Research at the University of Florida. However, the odds of being attacked by a shark in U.S. waters is one in 11.5 million, he said. For perspective, the average American has about a 1 in 5,000 chance of being struck by lightning during a lifetime. (Learn why we fear shark attacks.)

Related: Was This Whale Trying to Save a Diver From a Shark?

While shark attacks get all the media attention, you’re more likely to be attacked by a bear. McWilliams, who has been backpacking across the U.S. and Canada for the past few years, also managed to beat 1 in 2.1 million odds of being injured by a bear. Last July, a black bear bit him on the head while he was sleeping on a camping trip in Colorado. He escaped by poking the bear in its eye. Park authorities caught the bear, found McWilliams’ blood under the bear's claws, and put the animal down. It took nine staples to the back of his head to close McWilliams’ wounds.

“A North American black bear that attacks a human is generally hungry,” said outdoor writer Gordon Grice, author of The Book of Deadly Animals and “Shark Attacks: Inside the Mind of the Ocean's Most Terrifying Predator” (National Geographic Shorts). Such attacks are very rare, and usually because a bear has learned to associate humans with food by eating from bird feeders, trash cans, or pet dishes, he said. Between 1900 and 2009, just 14 people were killed by bears in the lower 48.

View Images Black bears are not known for being aggressive, but attacks on people occasionally occur. Photograph by Barrett Hedges, Nat Geo Image Collection

Maybe not so surprisingly given McWilliams’ luck, he managed to stumble onto a rattlesnake while hiking in Utah in 2015. He said the bite had little venom in it and decided not to go to the hospital, even though he was sick for a couple of days. The odds of being bitten by a venomous snake in the U.S. are estimated at 1 in 37,500. (The odds of being killed in a car accident are far more frightening at 1 in 112.)

“He’s one of the unluckiest guys on the planet,” says Burgess. How unlucky? Since each event is independent the odds of each are multiplied together, he said, making the odds of this happening 893.35 quadrillion to one.