Artist drawing horse behind farm animal (7)
I believe the answer is:
hogarth
'artist' is the definition.
(William Hogarth, 1697-1764)
'drawing horse behind farm animal' is the wordplay.
'drawing' becomes 'art' (I've seen this before).
'horse' becomes 'h' (synonyms).
'behind' is a charade indicator (letters next to each other).
'farm animal' becomes 'hog' (pig).
'art'+'h'='arth'
'arth' put after 'hog' is 'HOGARTH'.
(Other definitions for hogarth that I've seen before include "William --, English painter and cartoonist" , "Satirical 18th century painter" , "English painter and satirist, d. 1764" , "He painted" , "A Rake's Progress artist" .)