Rabbit, goat, or duck taken in by a useless artist (6)
I believe the answer is:
angora
'rabbit goat' is the definition.
'Angora' can be an answer for 'goat' (Angora goat is an example). I'm unsure of the 'rabbit' bit.
'duck taken in by a useless artist' is the wordplay.
'duck' becomes 'o'.
'taken in by' is an insertion indicator.
'useless' becomes 'ng' (I am not sure about this - if you are sure you should believe this answer much more).
'artist' becomes 'ra' (Royal Academician, member of Royal Academy of Arts).
'a'+'ng'+'ra'='angra'
'o' inserted into 'angra' is 'ANGORA'.
'or' acts as a link.
Can you help me to learn more?
(Other definitions for angora that I've seen before include "Cloth from the soft hair of a goat" , "Yarn or fabric made from goat hair" , "Woolly" , "Fabric made from goat or rabbit hair" , "Soft yarn from certain goats" .)