Cacodemon Christmas was an event started by Bungalo during Chirstmas 2005. Througout the days of December, various Cacodemon (an enemy from the PC game, Doom) related "gifts" were posted.
Cacodemon Christmases have appeared on MFGG every December since, though on a much smaller scale. In December 2008 Bungalo posted a Cacodemon Christmas fangame, and following this Black Squirrel named the Casual Conversation Castle after the event with a picture of a Santa-hat-wearing Cacodemon in the board's description. This eventually became a CyberCacodemonKing because of a Doctor Who special and was paired with several CyberWalruses.