Scurrilous critic having scrap in Angel (9)
I believe the answer is:
backbiter
'scurrilous critic' is the definition.
(I've seen this in another clue)
'scrap in angel' is the wordplay.
'scrap' becomes 'bit' (synonyms).
'in' indicates putting letters inside.
'angel' becomes 'backer' (angel can mean a financial backer).
'bit' put into 'backer' is 'BACKBITER'.
'having' acts as a link.
(Other definitions for backbiter that I've seen before include "Spiteful speaker" , "Sniper" , "Critic" , "Slanderer, maligner" , "Spiteful person" .)