Equipment to catch returning animal (6)
I believe the answer is:
kitten
'animal' is the definition.
(kitten is a kind of animal)
'equipment to catch returning' is the wordplay.
'equipment' becomes 'kit' (kit is a kind of equipment).
'to catch' becomes 'net' (netting is a kind of catching).
'returning' shows that the letters should be reversed in order.
'net' written backwards gives 'ten'.
'kit'+'ten'='KITTEN'
(Other definitions for kitten that I've seen before include "Young rabbit" , "Young Tom perhaps" , "New cat" , "Little feline" , "Mini-mog?" .)