His overall appearance is a skeleton dressed in a black pin-striped suit and a bow tie that strongly resembles a black bat. Originally, his suit was meant to be completely black, but it blended with the background too well, so it was changed. At the beginning of the film, Jack makes his grand entrance by emerging out of a fire-breathing dragon-themed fountain. His last name is based on the word "skeleton". He has a ghost dog named Zero for a pet, who has a small glowing nose that looks like a jack-o'-lantern. He is adored by Sally, a rag doll created by Dr. Finklestein. The character is a popular design on bags, hats, clothing, umbrellas, belt buckles, pet collars and other items.