Trinkets are items from SPY Fox in "Dry Cereal".
SPY Fox in "Dry Cereal"
In all versions of the storyline, SPY Fox can purchase the jar of trinkets from Gilbert at the Trinkets Booth, but it is only important to buy the jar of trinkets in the White Water storyline. The Jar of Trinkets are used so that SPY Fox can challenge Artimice J. Bigpig to a game of Go Fish any time he wishes (as there is an unlimited amount of trinkets inside).
In the White Water storyline, SPY Fox will need the jar of trinkets to challenge Artimice J. Bigpig so he can win back Captain Drydock's lucky charm.