Witch's cat (8)
I believe the answer is:
familiar
'witch's cat' is the definition.
(familiar can mean an animal belonging to a witch)
This is all the clue.
(Other definitions for familiar that I've seen before include "Conservant with the witch's cat?" , "Witch's cat is well acquainted" , "Well known from long association" , "Well-known, easily recognisable" , "Well known or recognisable" .)