Weighing in at over 600 kilograms, the bluefin tuna is a true titan prowling the oceans. Cyril is recruited by a team of biologists to travel along the East Coast of the United States and Canada to catch and tag one of these giants.

A gigantic fish lurking at the bottom of muddy rivers—this is the unsettling, elusive phantom Cyril has come to Thailand for; the giant stingray is arguably the largest freshwater fish on the planet.