Every second fat cat ready to have performed . . . (5)
I believe the answer is:
acted
'performed' is the definition.
(acting is a kind of performing)
'every second fat cat ready' is the wordplay.
'every second' means one should take alternating letters (I've seen 'every second of' mean this).
'fat'+'cat'+'ready'='fatcatready'
The alternating letters of 'fatcatready' are 'ACTED'.
'to have' is the link.
(Other definitions for acted that I've seen before include "Behaved like thespian" , "Feigned" , "exerted influence" , "Posed as" , "Pretended" .)