Mystery Box is a rare item found in the game Minions Paradise.
It is a grey box with golden and white margin and some question marks are carved of the surface.
When some Minions are upgraded in Minion Level-Up Building, sometimes mystery box spawns after harvesting resources if a level-up minion participates. It can be opened by clicking and often an extra stuff appears as a prize. In addition, if the minion is at the third level, the prize of the mystery box may be some rare-dropping items; if the minion is at the fourth (and the highest level), the prize can be 2 Doubloons.
Also, by watching a commercial, one of three mystery boxes can be chosen, and all the possible prizes inside include mixed stuffs, rare items, Sand Dollars or Doubloons.