I was playing multiplayer and beat the game, and someone joined in on Funkotron. They had the presents you get from Santa at spawn and used them, and upon trying to enter the North Pole, the game crashed on my end. Upon rejoining, it said everyone was at the North Pole, and I could press A to advance Loading Screen tips, but nothing further happened. I quit the game and joined another online game, and found that not only did I have the Santa presents, they duplicated endlessly until I dropped one out of my inventory. Afterwards they returned to normal, but I went through about 8 Boomboxes and Decoys before I realized what was happening.