Pied Piper's followers (4)
I believe the answer is:
rats
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">pied piper's followers</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is all the clue.<br/ ></span>
(Other definitions for rats that I've seen before include "were piped away" , "First word of 'The 21 19'" , "Tells" , "Heels" , "Mild oath - sewer residents" .)