If we called the polliwog (immature amphibian) a polwygle as our English forebears did five centuries ago, the source of the name might be more easily identified.
That is, poll, “head,” and wygle, which we now spell wiggle, a “wigglehead.”
Tadpole (which see) is the usual name in England; in America we use one or the other, whichever may first come to mind.
