Mythical mountain monster (4)
I believe the answer is:
yeti
<span class="explanation-format__ClueExplanation">'<span class="explanation-format__original">mythical mountain monster</span>' is the definition.<br/ ><span class="explanation-format__explanation">(I've seen this in another clue)</span><br/ ><br/ >This is the entire clue.<br/ ></span>
(Other definitions for yeti that I've seen before include "Legendary Himalayan creature" , "creature never actually seen" , "Himalayan mystery" , "Himalayan legend" , "An abominable animal!" .)