This season has six regular episodes, and the 1-hour Christmas special, in which Billy and Mandy try to save Santa Claus, who has been turned into a vampire. Characters that feature include Nigel Planter, trying to win the affections of a young witch; Principal Goodvibes, having a disastrous dinner with Billy, Hoss Delgado and Eris; Billy's parents, Harold and Gladys, becoming children again; Nergal, being a sore loser; the ghost of British poet Lord Byron, teaching Billy to be cool; the blue Schlubs (a parody of The Smurfs); and the ancient tentacled demon Cthulu. This season includes My Fair Mandy, the only episode in which Mandy willingly smiles, which causes unforeseeable consequences.