Dethmas is the Christmas special of Metalocalypse.
As Murderface and Knubbler prepare for their upcoming Christmas special (funded by the Christian church), Dethklok's mothers arrive for the festive season. Meanwhile, Toki goes gift shopping for his bandmates to discover that Dr. Rockzo has found a job as Santa Claus in a mall. Toki takes Rockzo back to Mordhaus. Murderface (tired of the band telling him that the Christmas special is going to suck) lies and says that it will be full off blood, gore and tits. Rockzo finds the presents Toki bought and sells them to buy cocaine. Christmas Eve arrives and Murderface and Knubbler host the Christmas special. Nathan becomes enraged due to the lack of brutality and goes to the studio. Simultaneously Dethklok's moms get drunk and Toki, who finds a few balloons in place of where his gifts used to be, sets off to kill Rockzo. Rockzo, the drunk moms, and Dethklok crash the Christmas special and the credits roll as Toki gets crushed by a large, wooden cross, Rockzo gets a handjob from Surfetta and Murderface gets brutally beaten by the head of the Christian church in front of a live TV audience.