The Guinean Giant Barracuda.
The African plains are home to nature's most fearsome predators. But the battle for survival is never one sided; even the prey can be formidable.
See lionesses fight against a bachelor lion for the safety of their cubs, and an over-confident mongoose try to scare away a pride of young lions.
Zeb heads deep into the Brazilian Amazon in search of an Electric eel large enough to kill a Caiman crocodile.
The Amazon's jungles reverberate with growls and grunts of creatures hidden in the trees and vying with one another for survival.