Hitch after cat does for small performer (3,5)
I believe the answer is:
tom thumb
'for small performer' is the definition.
(General Tom Thumb, dwarf circus performer)
'hitch after cat' is the wordplay.
'hitch' becomes 'thumb' (hitch-hiking).
'after' means one lot of letters go next to another.
'cat' becomes 'tom' (a tom is a male cat).
'thumb' put after 'tom' is 'TOM THUMB'.
'does' is the link.
(Other definitions for tom thumb that I've seen before include "Tiny hero of nursery tale - digital?" , "Panto character" , "Diminutive character of English folklore" , "General" , "Tiny child of fairy tale" .)