tadpole
/ˈtædpoʊl/
noun
- The aquatic larva of a frog or toad, with a tail and gills, before it develops legs and becomes an adult.
- The children caught a tadpole in the pond and watched it grow legs.
- In spring, the lake is full of tiny tadpoles swimming near the shore.
- A tadpole breathes through gills until it develops lungs.