Team's good luck bringer (6)
I believe the answer is:
mascot
'team's good luck bringer' is the definition.
(I've seen this before)
This is all the clue.
(Other definitions for mascot that I've seen before include "Lucky thing" , "Good-luck item" , "One is lucky" , "Team's good-luck bringer" , "Team's lucky person/thing" .)