Cat, goat or rabbit in Aragon strayed (6)
I believe the answer is:
angora
'cat goat or rabbit' is the definition.
(I've seen this in another clue)
'aragon strayed' is the wordplay.
'strayed' indicates anagramming the letters.
'aragon' is an anagram of 'ANGORA'.
'in' is the link.
(Other definitions for angora that I've seen before include "Fur of rabbit - hair of goat" , "Goat prized for its long silky hair" , "Long-haired cat, goat, or rabbit" , "Woolly" , "Soft yarn from certain goats" .)