Vâgner ventures into the world's largest rain forest to go head-to-head with the giant piraiba catfish. These megafish can stretch nearly 12 feet long and weigh a scale-busting 440 pounds. Though mainly preying on other fish, they have been known to eat birds and even monkeys. Local legend even tells of these powerful predators dragging fishermen to the river's bottom! Vâgner endures torrential rain and sleep deprivation to catch this mega catfish of the Amazon.