Nat Geo joins the search for an unidentified "highway beast" in Minnesota. Villagers in Southern Africa are stumped by round patches of sand that stretch over a thousand miles of landscape.

A popular surfing beach in Florida is known as the shark bite capital of the world, in England a mystery feline predator stalks the woods.

Nat Geo WILD investigates nature's most bizarre, baffling and downright mysterious cases.

What has caused hundreds of freshwater crocodiles to suddenly die in the Australian wilderness? Plus, a sterile mule in Morocco gives birth to a miraculous foal.

A mystery predator is turning Kruger National Park into a slaughterhouse; a bizarre, unidentified creature is caught on film in North Carolina.

Can reindeer really fly? And what is causing marine turtles to wash up dead and emaciated on the Great Barrier Reef?

How can rocks in Death Valley, CA move by themselves, leaving trails that stretch for hundreds of feet?

Does Vermont's Lake Champlain have its very own Loch Ness Monster? In Norway, a blue spiral light appears in the pitch black sky.

Can an extinct predator come back from the dead to terrorize a town? Why do millions of sardines swim to their deaths in a small harbour?

Five thousand blackbirds fall out of the sky one night in Arkansas. In the Scottish Highlands a sticky goo found on the ground has experts baffled.