How is the organism like both a fish and a four-legged vertebrate such as an ampibian?

The organism shares characteristics of both fish and amphibians through its dual life stages and anatomical features. Like fish, it typically possesses gills for underwater respiration during its early life stage, while later developing lungs for breathing air as it matures. Additionally, it has a backbone and a similar skeletal structure to both groups, allowing for locomotion in water and on land. This adaptability highlights its evolutionary link between aquatic and terrestrial environments.