A polar bear chases down Erin Greene as she walks home from a Halloween party in a small arctic town. A bull shark attacks triathlete Chuck Anderson in the Gulf of Mexico, biting his arm and pulling him to the ocean floor.

Jim Lane is picking blueberries alone in the Blue Ridge Mountains when a rattlesnake strikes. Teacher Rachael Lilienthal is swimming in a Florida river when an alligator bites down on her arm, pulls her underwater and doesn't let go.

A grizzly bear charges taxidermist Wilf Lloyd while he hunts elk with his son-in-law in the Canadian Rocky Mountains. Miles from shore, diving 180 feet below the surface, spearfisher Anthony Segrich finds a bull shark charging toward him.

Diver Tim Saxon films underwater at the Great Barrier Reef and gets stung by an Irukandji jellyfish, one of the world's most venomous animals. A grizzly bear attacks forester George Knoll in the remote Great Bear Rainforest.

A black bear charges Joe Azzouggagh and his German shepherd, Ace, deep in the Ontario wilderness. Single father Andrew Dickehage, forced to walk six miles along a rural road at night, comes under attack from unseen predators.

Andrea Schlake is volunteering at an animal sanctuary when a chimpanzee escapes its enclosure and chases her down. Surfer Todd Endris is ready to catch a wave when a great white shark knocks him off his board and attacks him.

Hiking in the Montana mountains, trail engineer Todd Orr is attacked twice by grizzly bear protecting her cubs. And, during a vacation in the Bahamas, Tiffany Johnson is snorkeling when she finds herself face to face with a tiger shark

Micki Glenn is attacked by a shark during a dive trip. Hours from the nearest medical facility, she has to rely on her husband and friends to save her life. And, a couple celebrating their wedding anniversary are attacked by a giraffe while on safari.

Paul Templer is leading a canoe safari on the Zambezi River near Victoria Falls when a hippopotamus bursts to the surface and drags him into the water; in Texas, an animal pounces on 5-year-old Jade DeMoss.

Wayne Petteway is attacked by an alligator while checking crab pots with his brother in North Carolina; in Arizona, Peter Baca is camping with his girlfriend and baby son when he is awoken by something attacking him through the walls of the tent.

Nicole Moore's vacation in Cancun, Mexico is cut short when she is attacked by a shark close to shore. In Tennessee, firefighter Kyle Watson and his family are hiking in the woods when he is bitten by a timber rattlesnake.

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Allena Hansen is working on her ranch in the California desert with her two rescue dogs when she is attacked by a black bear. And in Cancun, Mexico, Jonathan Schoeneman is spearfishing with his best friend when he comes face to face with a crocodile.

Catherine Dwinnell is hiking in Alaska when she is struck from behind and attacked by a 1,000 pound moose. In Hawaii, Tony Lee is swimming a half mile from shore when something grabs him and drags him below the surface.

Professional climber Greg Boswell is high up an ice-covered Canadian mountain in the middle of the night when he is charged by a grizzly bear. And in Upstate New York, a retired nurse is attacked by a rabid coyote.

Colorado park ranger Andy Peterson is hiking when he crosses paths with a mountain lion and its prey; in Vancouver, Kari Toft is walking her dog just steps from her home when she is attacked by a vicious raccoon.

Twenty miles into a marathon in a remote part of New Mexico, Karen Williams finds herself caught between a bear and her cub; Steve Campbell is working on an oil pipeline in Alberta, Canada, when a mountain lion attacks him.

On Christmas Eve, Matt Chenhall is walking with his two young daughters when he is attacked by a kangaroo; Lauren Fagen is volunteering at an animal sanctuary in South Africa when a lion reaches under a gate and pulls her legs through the bars.

A bull shark attacks a triathlete who is training in Alabama; a father fights to survive after a rattlesnake bites him; a giraffe attacks a couple in Zambia; a girls' trip turns deadly in Cancun.

Jordan Carbery is investigating a noise outside his cabin and encounters a massive grizzly bear. Days before their destination-wedding, Zanele Fox and her husband take a river tour when she is thrown from her raft and ravaged by a crocodile.

While having a beach day in Southern California, Leeanne Ericson is dragged under water by a great white shark; Braxton Rocha is attacked by tiger shark off Hawaii's northern coast.

In Texas, Jeremy Sutcliffe is working in his garden when a rattlesnake bite puts him on the brink of death; while spearfishing in the Bahamas, Kent Bonde is blindsided by a bull shark that tears the calf muscle from his leg.

On a family trip to Pattaya, Thailand, Helen Costigan attends an elephant show when one of the massive beasts turns deadly; golf ball recovery specialist Scott Lahodik is diving in a Florida lake when he's attacked by a vicious alligator.

Bob Legasa's hunting in Montana and what he thinks is a bluff charge from a grizzly bear is, in fact, a near-lethal attack; while canoeing in Zimbabwe, Kristen Yaldor's thrown into the water and finds herself in the jaws of a hippopotamus.

During an archery hunt in Cranbrook, British Columbia, Chad Dueck comes face-to-face with a mother grizzly bear; in Tracy, Calif., Walt Dean King is savagely attacked by a Brahma Bull roaming his neighborhood.