Hooded killer (5)
I believe the answer is:
cobra
'hooded killer' is the definition.
(I've seen this in another clue)
This is all the clue.
(Other definitions for cobra that I've seen before include "Sinuous creature" , "dangerous striker" , "hamadryad" , "Venomous hooded snake" , "Venomous snake, may be king" .)