“Crabby” types making a living, excellent actors originally (9)
I believe the answer is:
crustacea
'crabby types' is the definition.
(subphylum including crabs)
'a living excellent actors originally' is the wordplay.
'a living' becomes 'crust' (to earn a crust is to earn a living).
'excellent' becomes 'ace' (I've seen this before).
'originally' suggests taking the first letters.
The initial letter of 'actors' is 'a'.
'crust'+'ace'+'a'='CRUSTACEA'
'making' is the link.
(Other definitions for crustacea that I've seen before include "crabby group?" , "Group including lobsters, crabs, etc" , "Prawns and lobster" , "shellfish" , "Collection of hardbacks" .)