Nintendo UK has released two special codes that allow players to redeem a Hamburger Hat costume set.
The special codes can be found in the image below. Instructions can be found following the images. More codes can be found here.
To get these items, simply follow these steps to enter a special code into the game:
1. On the Ferrum Region map screen, press the X Button to enter the System Menu
2. Select the Special Code option
3. Enter the code when prompted
Once you’ve arrived at the Special Code entry screen, enter the following code to claim your rewards!