Jack is selfish and wants to be Santa for his own gain. He schemes and tricks Scott into relinquishing his Santa role. Jack is rude to kids and adults, "frosts" people, and causes Christmas chaos everywhere.
Some slapstick violence: Scott gets smacked in the face with a shovel; in another scene, his pants are on fire. Jack gets knocked over. Also, Santa falls off a roof and disappears -- literally -- leaving behind only his clothes.
Mrs. Claus is pregnant.
Toys and snow globes factor greatly into the storyline.