Continuity mistake: When Jack is having his Santa joyride, the army is called in to shoot him down. There is one sweeping shot of the giant cannons rising and firing at him. If you look at the bottom of the screen, you can see two small soldiers as the guns are rising, but as they fire, the soldiers blink out of existence.
Trivia: In the song "This is Halloween," the two children sing "Tender Lumplings everywhere..." This is a reference to a poem from the film's songwriter/composer/Jack's singing voice, Danny Elfman's, former musical theatrical street troupe, The Mystic Knights of the Oingo Boingo (later to evolve as Oingo Boingo.) The original poem, Tender Lumplings, was "And so my tender lumplings, let my welcome hear you now/Into our flesh-pink home of hearts we greet you with a bow/So entertain we must we may, our pleasure from within/The Oingo Boingo treasure chest of lust and mortal sin."