Flier seen as headless chicken (5)
I believe the answer is:
raven
'flier' is the definition.
(raven is a kind of birdanimal)
'headless chicken' is the wordplay.
'headless' means to remove the first letter.
'chicken' becomes 'craven' (I've seen this before).
'craven' with its initial letter taken off is 'RAVEN'.
'seen as' acts as a link.
(Other definitions for raven that I've seen before include "Species of crow" , "Flier" , "Flighty type" , "Flyer" , "Bird of ill omen" .)