Dickensian villain beheaded farm animals (4)
I believe the answer is:
heep
'dickensian villain' is the definition.
(Uriah Heep, villain in Dickens' David Copperfield)
'beheaded farm animals' is the wordplay.
'beheaded' means to remove the first letter (the head of the word is removed).
'farm animals' becomes 'sheep' (sheep are farm animals).
'sheep' with its first letter removed is 'HEEP'.
(Other definitions for heep that I've seen before include "Uriah . . . . , Dickens hypocrite" , "lawyer's clerk" , "Uriah . . . ., arch-hypocrite in 'David Copperfield'" .)