Coach about nine new pets (7)
I believe the answer is:
bunnies
'pets' is the definition.
The definition and answer can be both animals as well as being plural nouns.
Perhaps they are linked in a way I don't understand?
'coach about nine new' is the wordplay.
'coach' becomes 'bus' (synonyms).
'about' indicates putting letters inside.
'new' is an anagram indicator.
'nine' is an anagram of 'nnie'.
'bus' enclosing 'nnie' is 'BUNNIES'.
Can you help me to learn more?
(Another definition for bunnies that I've seen is " Rabbits".)