Summary: Rivers aren't exactly where you'd expect to find giant 1,000-pound monsters, but that is exactly where Dr. Zeb Hogan plans to research giant freshwater rays. His journey starts in the Northern Territory of Australia, where Zeb searches for whiprays, a rare species that was properly identified only in the past few years! After catching mostly bull sharks, Zeb turns his attention to Thailand's giant freshwater stingray. On the Mae Klong River, he battles a 385-pound behemoth for hours.

Summary: Dubbed Frankenfish, the snakehead is a prized fish in Thailand that looks more like a snake than a fish. Snakeheads are ferocious predators, rumored to be able to walk on land, breathe air and attack humans. They've spread to the waters of the U.S., and fish biologist Dr. Zeb Hogan is on a mission to catch a monster snakehead. He starts off in Florida, which has come under attack by the invasive bullseye snakehead, one of the biggest of the species. Then, he travels to Thailand.

Summary: Biologist Dr. Zeb Hogan treks into the Nicaraguan rainforest in search of the powerful giant tarpon - a 300-pound fish that takes fishermen hours to reel in.