Some horribly etiolated creature found in mountains? (4)
I believe the answer is:
yeti
'creature found in mountains?' is the definition.
'some horribly etiolated' is the wordplay.
'some' says the answer is hidden in the clue (some of the parts of the word are used).
'YETI' is hidden in the letters of 'horribly etiolated'.
(Other definitions for yeti that I've seen before include "Hairy creature of legend" , "whose existence is unconfirmed" , "A legendary animal" , "seeks him in the Himalayas" , "Highly elusive monster" .)