A complete career change...
The word amphibian comes from the Greek amphibios meaning "both lives". This is an apt description because most adult amphibians are better adapted to life on land than in water, while their larval phases are entirely aquatic.
For much of their lives, which may last a couple of months or several years depending on the species, larval amphibians bear little resemblance to their adult forms. Then something miraculous happens. In a matter of weeks or even days, the once fish-like larvae metamorphose into terrestrial, air-breathing quadrupeds!