Other forms: polliwogs
A polliwog is a baby frog or toad. While as adults they'll have strong back legs that allow them to hop around on land, polliwogs have tails and live in the water.
A polliwog is another word for a tadpole, the earliest stage in the life of an amphibian. Polliwogs are aquatic, living entirely in water and propelling themselves with their tiny tails. The process of a polliwog becoming a full-grown frog or toad is called metamorphosis, and it includes the growth of legs and lungs — and the loss of the tail. Even though they sound unrelated, polliwog and tadpole share the root word pol, "head."