National Geographic Wild X Files

Investigators examine a strange, unidentified creature that washed ashore at Montauk, Long Island. The investigation explores the creature's possible identity and the evidence that might explain this unusual discovery.

In 2007, a giant web engulfed a forest in Lake Tawakoni State Park, East Texas. What creature was behind the web – and why was it spun?

Investigating the mysterious death of a number of toads in Hamburg, Germany in 2005, all of whom died by spontaneously exploding.

In Scotland, a reporter uncovers a 60-year history of dogs leaping from the same bridge. In India, a strange boom is heard and red rain falls.

In 2003, predatory Humboldt squid threaten the fisheries of California's Monterey Bay. Plus, a plague of mice hits Australia.

A six-foot-long creature is launching itself at pigeons from a Spanish river. Journalist Andy Allen investigates.