The day before Christmas, Billy, Mandy and Grim go to the shopping mall, where Mandy complains that Santa Claus is just an invention from corporations. However, Grim assures Mandy that Santa is real, and they even went to college together. Then, they decide to travel to the North Pole and meet Santa, but when they arrive Mrs. Claus (Carol Kane) tells them that Santa Claus (Gilbert Gottfried) has been transformed into a vicious vampire. Then, to save Christmas, Mandy and Grim go to stake the Head Vampire, Baron Von Ghoulish (Malcolm McDowell), while Billy remains with Mrs. Claus to look after her. However, it turns out that the cleaning-obsessed Von Ghoulish is not the vampire they are looking for, so they set out to find the Head Head Vampire. Then, Mandy, Grim and Von Ghoulish go back to Santa's workshop where it is revealed that Mrs. Claus is in fact the Head Head Vampire, and it was she who transformed Santa, which she did so she could take a break from all her work. Then, Billy fin