The 25 Day Chest is a daily reward that you get just for opening up the game. New players should open CWK once a day in order collect the rewards which vary and include: Gems, Coins, Wishbones, Cake, Hearts, and Creatures. The ultimate prize is an Algebraic Creature on the 25th Day.
NOTE: the Algebraic Creature that you get from the 25th Day Chest will be at level 1. The only other way to get a level 1 Algebraic Creature is to purchase it from an in game sale.
25 Day Chest ExploitEdit
The clock in CWK is not very good. If you watch it during the times when you collect your adventure loot you will notice that it moves forward and back each time you collect. This is also observable at midnight when you check your daily missions.
If you quit the game and reboot at midnight multiple times, it is possible to collect several 25 Day Chests in a row. Players report collecting up to seven chests in a row, but two or three are generally all you will get. Be careful about doing this for the 25th chest as the game has sometimes skipped this chest.