Beastly cry from yours truly: 'That hurt!' (4)
I believe the answer is:
meow
'beastly cry' is the definition.
'yours truly that hurt' is the wordplay.
'yours truly' becomes 'me'.
'that hurt' becomes 'ow' (I've seen this in other clues).
'me'+'ow'='MEOW'
'from' is the link.
(Other definitions for meow that I've seen before include "Cry of a cat" , "reply to spiteful dig" , "Tom's plea for attention" , "Cat's cry" , "Crying sound of an animal" .)