King's Credits
From MHWiki
Congratulations! You've been awarded a King's Credit! Visit the royal prize shop to claim a prize of your choice, or keep saving up to redeem greater rewards!
King's Credits are awarded during the King's Giveaway, and are the only currency accepted in the Prize Shoppe. They can be obtained by catching prize mice: Treasurer, Snooty, or High Roller. A Hunter with a higher Prize Power is more likely to encounter a prize mice.
A hunter can determine their current number of credits with this in-game link. Credits can only be spent during a giveaway event, but can be saved for use in a future event.