Lucky thing (6)
I believe the answer is:
mascot
'lucky thing' is the definition.
(I've seen this before)
This is the entire clue.
(Other definitions for mascot that I've seen before include "Thing supposed to bring good luck" , "'Symbol, for a team say (6)'" , "Thing considered to bring good luck" , "Lucky charm" , "Character or object used to bring good luck, or represent an organisation" .)