Immature frogs (8)
I believe the answer is:
tadpoles
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">immature frogs</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for tadpoles that I've seen before include "Little swimmers" , "Larvae of frogs or toads" , "Baby frogs" , "Stop deal (anag.)" , "Pond-life" .)