Nigel Marven travels to the world's largest wetland in Brazil in pursuit of the elusive jaguar. The Pantanal is home to a vast array of wildlife and boasts the planet's largest population of jaguars - the least known of the big cats. In the opening episode, Nigel tussles with a caiman; endures a painful encounter with a false water cobra; glimpses an elusive tapir; and interrupts a pair of mating anacondas.