If you’ve played the Banjo-Kazooie games, you may know about Stop ‘n’ Swop, a special feature that involves six different-colored mysterious eggs and an ice key used to unlock rewards. Since Stop ‘n’ Swop is a popular topic among players, Playtonic Games came up with a similar feature in Yooka-Laylee. Instead of different colored eggs, the developers opted for crystal skulls, known as Pirate Treasures, while each Grand Tome of Hivory Towers contains a Pirate Treasure, usually hidden at a spot that is easily overlooked by players. According to the Internet, the skull located in the fifth world, Galleon Galaxy, is the hardest one to find because its hiding place is atypical in comparison to other collectibles in the game. Whenever the player picks up a Pirate Treasure, a dark, creepy and dramatic sounding organ tune plays, whereupon the crystal skull disappears in Yooka’s inventory. Beside of that, all Pirate Treasures that have been collected won’t appear in a separate window like the Stop ‘n’ Swop items did in Banjo-Kazooie. At the moment, the purpose of these skulls is unknown, but due to the similarities with Stop ‘n’ Swop players can assume that Pirate Treasures will unlock special rewards in the sequel games of Yooka-Laylee. Although they have no use yet, the player can unlock three achievements by finding all five Pirate Treasures.