Answer: polliwog

AnswerCrossword Clue
POLLIWOGTadpole
POLLIWOGGill-breathing amphibian
POLLIWOGIt grows older and then croaks
POLLIWOGFuture frog
POLLIWOGFrog to be
POLLIWOGFrog, almost
polliwogA tadpole
polliwoga tadpole.