The Silver Prize Pod is an item in Minion Rush. In original game design, after collecting three Bapples in a day, the player could receive a silver prize pod. From the silver prize pod, the player can receive either one of coins, costume cards, revives, tokens, or boosters/perks.
However, after the 5-Year Celebration update, it was replaced by Video Ad Prize Pod that you can get by watching an ad. You can get new Minion costumes by opening these pods. However, in 6.8.1 update, Free/Video Pod is merged into the Silver one.
Video Ad Prize Pod.