Amphibians and reptiles get the attention David Attenborough spent decades reserving for warm-blooded animals, in this BBC series he writes and presents himself. He argues these creatures are often dismissed as primitive because they are cold-blooded, then sets out to show the opposite: complex courtship displays, parental care, and hunting strategies refined over hundreds of millions of years. The series moves across habitats worldwide, tracking snakes, lizards, frogs, salamanders, turtles, and crocodilians through behavior filmed for the first time on this scale. Attenborough's narration stays close to the animals themselves, using each sequence to make a case for reptiles and amphibians as evolutionary successes rather than footnotes to the age of mammals and birds. It was made as the concluding chapter of his long-running Life project, closing out a group of animals earlier series had largely passed over.