The Nightmare Before Christmas is an animated film by director Tim Burton. The film was released in 1993 but characters from the Nightmare Before Christmas like Zero, Jack Skellington, and Sally became instant cult favorites. Today characters from The Nightmare Before Christmas are an intrinsic part of Halloween.  Music from the animated film is played every year at Halloween and classics like "What's This?" and "This is Halloween" are Halloween favorites.
The story of The Nightmare Before Christmas is the story of Jack Skellington, The Pumpkin King of Halloween Town. Jack is a skeleton who wears a tuxedo and leads the Halloween festivities every year in Halloween Town and in the outside world. Halloween Town is populated by all the creatures associated with Halloween like witches, ghouls, goblins, ghosts, monsters, spiders, bugs, creepy crawlies and bats.  Jack starts to grow bored with traditional Halloween celebrations and he starts to wonder what else is out in the world. One day he and his ghost dog Zero manage to open a hidden portal to Christmas town. Each holiday has its own town in Burton's delightfully weird world. Jack and Zero visit Christmas Town and experience snow for the first time. Jack is enraptured by the elves making toys and by Santa Claus. He decides he wants to be Santa Claus this year.
Back in Halloween Town he starts hatching a plan to kidnap Santa and take his place giving out presents. He confides his plan to his friend Sally. Sally was created by Halloween Town's resident mad scientist who treats her as a servant. Sally is in love with Jack. She tells Jack that his plan is going to fail but he refuses to listen to her. He sends three unruly mischievous kids, Lock, Shock and Barrel who are Halloween pranksters to kidnap Santa and keep him out of the way until Jack can take over Christmas. The three kidnap Santa but instead of keeping him safe they take him to Oogey Boogey, who threatens to kill Santa. As Christmas day arrives Jack refuses to listen to anyone who tells him that his plan is a bad one. He loads up a ghostly sleigh with Zero and lots of Halloween presents like severed heads and spiders. He has a crew of skeleton reindeer who are led by Zero, whose nose glows red like Rudolph's nose.
Once Jack starts delivering presents and kids start opening their severed heads and other Halloween themed gifts the parents alert the authorities and the military is called in to shoot Jack's sleigh out of the sky. Miraculously, Jack survives and manages to get back to Halloween Town although he is bitterly disappointed. When he gets back he finds out that Sally has gone to rescue Santa and has been imprisoned by Oogey Boogey. Jack frees Sally and Santa, and returns Santa to Christmas Town. In the end he and Sally kiss in the moonlight of Halloween Town after Jack promises never to attempt to take over another holiday.