YOU'VE MADE IT THROUGH HALLOWEEN, NOW TRY AND SURVIVE CHRISTMAS.
Little Billy witnesses his parents being brutally murdered by Santa. Years later, when he has to fill in for an absent in-store Santa Claus, his childhood trauma materializes once again.
Might as well just watch part 2. The story is that the first was pulled from theaters due to a whiny "moms against fun" type of group and they wanted to re-release it. They shot an intro and interstitials and re-edited the original but had enough new content that they just called it part 2.
So essentially part 2 is almost the entirety of part 1 plus eyebrow acting, garbage day, and stunts.