Jack Skellington

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 immortal 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, is in charge of Halloween Town's Halloween celebration, a role for which he receives respect and admiration from the other residents. However, monologue with himself reveals he is growing tired of celebrating the same holiday endlessly. Jack's sense of adventure is stimulated when he accidentally discovers Christmas Town, driving him to start a Christmas celebration of his own. While his intentions are good, Jack does not understand the true spirit of Christmas, and he and his fellows give it a macabre hue.

Ultima role
Jack appeared in ultima, equipted with the Soul rubber from the game, while defending the Safe house when been attacked, he seem to know and friends with Grim.