Fish biologist Zeb Hogan is looking for one of the freakiest fish in the world; vampire fish, known locally as payara, weigh up to 40 pounds, hunt like great white sharks and have terrifying 6-inch fangs.

Zeb Hogan explores the maze-like river systems of Argentina on a quest to catch a colossal 400-pound short-tailed river ray, the largest freshwater stingray found in South America, and uncover the surprising sting it's hiding in its tail.

Zeb is in a town called Albi in southern France to see a giant Wels catfish for himself.

Zeb explores Florida's deep-water reefs and wrecks on a mission to catch a gargantuan 7-foot goliath grouper, the largest of the western Atlantic groupers, and uncover the surprising truth about its monstrous reputation.