Wild animal that could be orange (6)
I believe the answer is:
onager
'wild animal' is the definition.
'could be orange' is the wordplay.
'could be' indicates an anagram.
'orange' with letters rearranged gives 'ONAGER'.
'that' is the link.
(Other definitions for onager that I've seen before include "wild beast" , "ancient weapon" , "Variety of wild ass found in central Asia" , "donkey" , "Asian wild ass - orange (anag)" .)