2006 | 11 Episodes
This season has 11 regular episodes. Midway through the season, the special episode Billy and Mandy Moon the Moon was showed, and the TV movies Billy & Mandy's Big Boogey Adventure and Billy & Mandy: Wrath of the Spider Queen aired. In this season, special appearances are made by Pinface (a parody of Pinhead from Hellraiser); the mummy of the Pharaoh Poppin Lockin, who is Irwin's maternal grandfather; the Abominable Snowman, who is to be reaped by Grim; King Triceps, ruler of the ocean, and his daughters Hariel and Uvula (parodying The Little Mermaid); Hector Con Carne and Major Dr. Ghastly (from Evil Con Carne), who try to recruit General Skarr back to their army; Lionel Van Helsing, a vampire hunter seeking to destroy Dracula; and Del Uglio, a Mexican luchador, who turns out to be Billy's twin brother. In addition, Lord Pain returns, now serving Mandy, instead of Grim; the Secret Snake Club is also back, now trying to avoid physical education; Nergal and his family engage in a pizza war against Billy, Mandy and Grim's own pizzeria; Nergal Junior and Irwin battle for the love of Mandy; Dracula is revealed to be Irwin's paternal grandfather; Nigel Planter discovers the truth behind the scar in his forehead (parodying Harry Potter); and Billy, Mandy and Grim find themselves in Mexico to save the Dia de los Muertos festivity. In Heartburn, the last regular episode of the series, Mandy overcomes her dark nature, and finally kisses Irwin. However, she quickly goes back to her old self.