Legless reptiles (6)
I believe the answer is:
snakes
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">legless reptiles</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this before)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for snakes that I've seen before include "Adders, cobras, rattlers etc" , "[CREES]" , "Scaly reptiles" , "Legless reptiles" , "Limbless reptiles" .)