This DLC contains the hero attire: Santa's Helper's Costume

Of course Santa can't be everywhere at once: Hence the blue costumes of his innumerable helpers, who give out gifts and joy to friends and loved ones.

The above DLCs can be claimed by talking to the Town Crier in a capital or the Trade Colonies after purchase.
Note: This DLC contains a hero attire which only changes the wearer's appearance, not their attributes.