Animal artist with a long-famous model (3)
I believe the answer is:
rat
'animal' is the definition.
(rat is a kind of animal)
'artist with a long-famous model' is the wordplay.
I cannot really see how this works, but
'artist' could be 'ra' (Royal Academician, member of Royal Academy of Arts) and 'ra' is found within the answer.
'model' could be 't' (Ford Model T car) and 't' is located in the answer.
No letters remain.
This may be the basis of the clue (or it may be nonsense).
Can you help me to learn more?
(Other definitions for rat that I've seen before include "Tell-tale" , "one not going down with ship" , "One deserting sinking ship" , "Betrayer" , "one escaping doomed vessel?" .)