Shaver returned large sea creature! (9)
I believe the answer is:
razorback
'large sea creature' is the definition.
The definition and answer can be both animals as well as being singular nouns.
Maybe they are linked in a way I don't understand?
'shaver returned' is the wordplay.
'shaver' becomes 'razor' (I've seen this in another clue).
'returned' becomes 'back' (I've seen this in other clues).
'razor'+'back'='RAZORBACK'
Can you help me to learn more?
(Another definition for razorback that I've seen is " One grunting".)