Balaam's beast (3)
I believe the answer is:
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">balaam's beast</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 ass that I've seen before include "Clinton's behind" , "Jennet" , "Animal; fool" , "Hoofed animal, smaller than a horse" , "jack" .)