16a (4) Too colossal, something's captured ---O
22a (6) Emperor races off round front of amphitheatre ---S-R
17d (5) All over the mother animal --A--
11a (4) Urge to take leader off field --C- Is this ITCH? And would 6d (7) be AMUSING? Although I cannot see how the clue works: Funny seeing a crime in vessel.
Thanks all for any help!