Tadpole
A tadpole is the aquatic, gilled larva of a frog or toad that hatches from spawn and gradually grows legs, absorbs its tail, and metamorphoses into a tiny froglet.
Tadpoles need clean, dechlorinated water, the right food, and — as they grow legs — a way to climb out before they drown. Raising them is rewarding but a real commitment, and you'll need homes for the froglets.