In the icy waters of Alaska, off populated beaches of New York and lurking in ghostly shipwrecks off the coast of North Carolina, scientists have discovered three sharks that have developed unique and deadly ninja skills.

In Mexico, legends swirl around El Demonio Negro, a 50-foot shark that has terrorized fishermen and tourists alike for generations. Is this an undiscovered predator? Forrest Galante hunts for answers in the most rugged and remote parts of the Baja Peninsula.