Menace in "Raiders of the Lost Ark" (3)
I believe the answer is:
asp
'menace in raiders of the lost ark' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for asp that I've seen before include "Reptile" , "Slithery thing" , "Cleopatra's supposed nemesis" , "the snake in Cleopatra''s bosom" , "Snake, killed Cleopatra" .)