Harmless rattler
I believe the answer is:
maraca
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">harmless rattler</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 maraca that I've seen before include "One of a pair of hollow pieces of wood or bone for Spanish dancing" , "Instrument made from a filled gourd" , "Percussion instrument played in pairs" , "'Hand-held percussion instrument, hand-held (6)'" , "Rattle used as a rhythm instrument" .)