Jack Skellington is the patron spirit of Halloween, portrayed as being on par with Santa Claus and the Easter Bunny within his own holiday. As a living skeleton, he is supernatural and can remove parts of his body without harm, as is often demonstrated for comic relief. He is the most important of many Halloween spirits, with the implication that their job is to scare people in the real world on Halloween night.
Jack, as the “Pumpkin King” and Master of ceremonies, is in charge of Halloween Town’s Halloween celebration. He is respected and even idolized by the other residents for his role, but he has grown weary of celebrating the same holiday endlessly and is depressed about it. The only one who understands Jack’s feelings is a lonely ragdoll named Sally. She overhears his singing monologue and feels she can relate to his situation.
Jack discovers Christmas Town and decides that this new experience is what his life was missing. He makes plan for his own Christmas celebration in Halloween Town and wants to impersonate Santa Claus in the real world. While his intentions are not malicious, Jack does not understand the true spirit of Christmas. Halloween Town plans to give the holidays a macabre make-over. Sally reveals to Jack a bad premonition, but Jack’s basic nature is impulsiveness. He does not seem to register contradictory information. By the end of the film, he notices Sally and her determination to help him. He proves that love can be a part of his nature by calling Sally his “Dearest Friend”, telling Sally that they were meant to be together, embracing his future with her and embracing her.