Here's a Christmas Season-appropriate random mystery/horror adventure outline generator that was inspired by a combination of a drawing by Bryan Baugh and a spooky version of "Carol of the Bells" by rock group Halocene. (The video and song can be enjoyed at the bottom of this post.)
THE SANTA SLAYINGS
The beautiful people are being hacked to death with an axe and various objects associated with Christmas are left scattered about the bodies. Witnesses report a decidedly non-jolly, white bearded man has been spotted near each of the murders. Can the heroes stop the slaughter before the happy goes completely out of the holidays for everyone?
WHEN DO THE MURDERS START? (Roll 1d6)
1. July 24 ("Christmas in July")
2-3. November 20.
4-5. December 12 ("The 12th Day of Christmas")
6. December 25 ("The 12 Days of Christmas")
WHO IS KILLED? (Roll 1d6)
1. A Family (Mother, Father 1-6 children)
2. Drunken Partiers (1d6+1 Guys, 1d6+1 Girls)
3. Sexy Santas (1d6 Girls, 1d6-1 Guys)
4. Church Choir Members (2d6 Guys, 2d6 Girls)
5. Toy Company Executives (1d6)
6. Activists (1-3 Pro Christmas, 1d6 killed; 4-6 Anti Christmas, 1d6 killed)
HOW OFTEN DOES THE KILLER STRIKE? (Roll 1d6)
1. Every 1d6 hours.
2. Every 2d6 hours.
3. Every other day until 12 days have passed. He then goes quiet until next Christmas.
4. Every third day until 12 days have passed. He then goes quiet until next Christmas.
5. Every third day until stopped.
6. The strikes three times, 2d6 hours between killings. He then comes for the player characters.
WHO IS KILLED NEXT?
Roll 1d6 on the WHO IS KILLED table each time the killer strikes. There are 1d6-1 survivors who describe the killer as "Santa Claus."
WHO IS THE KILLER, AND WHY DOES HE KILL? (Roll 1d6)
1-2. A Psychopathic Mall Santa Who's Blossomed into a Serial Killer Who Hates Those Who Love Christmas.
3-4. An Insane Religious Fanatic Who Punishes Those Who Aren't Keeping Christmas Holy.
5. A Demon Who Was Accidentially Summoned By a Church Group Who Was Praying for God to Punish Those Who Don't Observe the Proper Christmas Spirit. (They were actually the first victims, and the party may discover this during their investigation.)
6. It's Santa Claus Who Has Snapped and Decided That Anyone Who Is Naughty Must Die.
HOW IS THE KILLER STOPPED? (Roll 1d6)
1. By making him understand the meaning of Christmas, so he will willingly be brought to justice.
2. By killing him.
3. By cornering him and forcing him to surrender to be brought to justice.
4. By killing him.
5. By performing a magical ritual involving milk and cookies that will calm the murderous creature and make him regret what he has done and allow him to return to his . (Works only on the Demon and Santa.)
6. By killing him.