Brazilian ranchers are turning up dead, gored by some unknown creature. There's a wide range of animal suspects from jaguars to caimans, but could the killer be something no one suspected?

Hundreds of endangered Ridley Sea Turtles are turning up dead and half eaten along the beach in Costa Rica during the monthly Arribata. But could the predator be from the land or sea or both?

In the jungles of Luzon Province, locals believe a vampire-like evil spirit has begun picking off villagers and livestock, taking them away without a trace. But could this in fact be new behavior from a frightening jungle predator?

Kangaroos are being mauled in Victoria, Australia. The wounds mimic those seen by lions, tigers and cougars in other parts of the world, but there are no big cats in Australia. Has a long-extinct predator returned?

Crocodiles, the apex predator of Australia's Northern Territory, are mysteriously showing up dead, belly-up in the water, with no clear sign of visible trauma. What could be taking down this vital animal with no known predators?