Nobbled animal about to finish last (3,2)
I believe the answer is:
got at
'nobbled' is the definition.
(I've seen this before)
'animal about to finish last' is the wordplay.
'animal' becomes 'goat' (I've seen this before).
'about' means one lot of letters goes inside another.
'to finish' suggests the final letters.
The last letter of 'last' is 't'.
'goat' going around 't' is 'GOT AT'.
(Other definitions for got at that I've seen before include "Unfairly influenced" , "Nobbled" , "Attacked verbally" , "Criticised" .)