Amphibians are members of the class Amphibia, a group of vertebrates whose living forms include frogs, toads, salamanders, newts and caecilians. They are characterized as non-amniote, ectothermic tetrapods, meaning their eggs are not surrounded by membranes, they are cold-blooded, and they have four limbs. Most amphibians lay their eggs in water and the larvae undergo metamorphosis from a juvenile form with gills to an adult air-breathing form with lungs. Some, however, are paedomorphs that retain the juvenile water-breathing form throughout life. Mudpuppies and olms are examples of this, retaining juvenile gills into adulthood. Adult amphibians also use their skin for respiration.

The three modern orders of amphibians are placed in the subclass Lissamphibia and are the Anura (frogs and toads), Caudata (salamanders and newts) and Gymnophiona (caecilians, limbless amphibians that resemble snakes). The total number of known amphibian species is approximately 7,000. They are superficially similar to reptiles, but reptiles, along with mammals and birds, are amniotes, having impervious membranes that surround the egg. Amphibians are ecological indicators, and in recent decades there has been a dramatic decline in amphibian populations around the globe. Many species are now threatened or extinct. The study of amphibians is called batrachology.

Sir David Frederick Attenborough ( /ˈætənbərə/) OM, CH, CVO, CBE, FRS, FZS, FSA (born 8 May 1926) is a British broadcaster and naturalist.

His career as the face and voice of natural history programmes has endured for more than 50 years. He is best known for writing and presenting the nine Life series, in conjunction with the BBC Natural History Unit, which collectively form a comprehensive survey of all life on the planet. He is also a former senior manager at the BBC, having served as controller of BBC Two and director of programming for BBC Television in the 1960s and 1970s.

Attenborough is widely considered a national treasure in Britain, although he himself does not care for the term. He is a younger brother of director, producer and actor Richard Attenborough.

Attenborough was born in Isleworth, west London, but grew up in College House on the campus of the University College, Leicester, where his father, Frederick, was principal. He is the middle of three sons (his elder brother, Richard, became an actor and his younger brother, John, an executive at Italian car manufacturer Alfa Romeo). During World War II his parents also adopted two Jewish refugee girls from Europe.

Conan Christopher O'Brien (born April 18, 1963) is an American television host, comedian, writer, producer and performer. Since November 2010 he has hosted Conan, a late-night talk show that airs on the American cable television station TBS.

O'Brien was born in Brookline, Massachusetts, and raised in an Irish Catholic family. He served as president of the Harvard Lampoon while attending Harvard University, and was a writer for the sketch comedy series Not Necessarily the News. After writing for several comedy shows in Los Angeles, he joined the writing staff of Saturday Night Live, and later of The Simpsons. He hosted Late Night with Conan O'Brien from 1993 to 2009, followed by seven months hosting The Tonight Show with Conan O'Brien, the only person to serve as the permanent host for both NBC programs.

O'Brien was born in Brookline, Massachusetts (a suburb of Boston) to Thomas O'Brien, a physician, epidemiologist, and professor of medicine at Harvard, and Ruth O'Brien (née Reardon), an attorney and partner at the Boston firm Ropes & Gray. He is the third of six children. O'Brien's family is Irish Catholic and descends from pre-Civil War era immigrants. In a Late Night episode, O'Brien paid a visit to County Kerry, Ireland, where his ancestors originated.