Dodos
(Another definition for morons that I've seen is " fools".)
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">dodos</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 asses that I've seen before include "Animals of horse family" , "Idiots" , "More than one fool" , "Dolts" , "Fools; beasts of burden" .)