Smokey Castle

Smokey Castle is the challenge level of Dragon Forest in Diddy Kong Racing and its remake, Diddy Kong Racing DS. It becomes accessible after the player's racer collects the Wish Key of Boulder Canyon. In the Nintendo DS remake, the stage can be unlocked from Taj's Wishes Menu by paying 30 coins for the "Battle Stage 4" option, and it is only playable in multiplayer mode.

The battle takes place in a square-shaped castle. Inside the castle are four treasure chests, each depicting the character that it belongs to. The purpose is for racers to collect bananas and take them to their treasure chest. Racers can only carry up to two bananas at a time. Racers can lose their bananas if they are hit by a weapon. Once bananas have been placed on a chest, they cannot be lost. The first racer to put ten bananas into their treasure chest wins. If the player's racer wins, they obtain the fourth and final piece of the T.T. Amulet.

In the Nintendo DS remake the bananas are replaced by Taj Tokens, and the racers can carry up to five of them.