Two of my favorite house idea series I came up with are the anthology series Christmas Creep and the even more disjointed Monster Music.
What if they had an unholy bastard spawn?
CHRISTMAS CREEP and MONSTER MUSIC PRESENTS: HOLIDAY HORROR HITS
To quote the announcer from Homestar Runner's Decemberween Mackerel, "Oh dear God, what have we done?"
There are many other quotes that could work here, but that's the most festive by association.
...not a whole lot to explain here. I'm just buying time before I have to make the room list.
Well, as a Christmas-themed spinoff, a few rules are broken. (Weird Al features... TWICE?)
Well, time to roll.
Facade: An abandoned music hall, decorated in broken decorations. The wreaths are dead, the trees are dead, the string lights flicker, the ribbons are torn. The marquee has the house title, and posters are displayed of the featured performers. Spirits lurk around, projected as shadows on the facade.
Christmas At Ground Zero: Guests step out of a fallout shelter to find a world abandoned at Christmastime. Decayed buildings with decayed Christmas decor, graffiti with dark Christmas humor messages, obvious signs of looting, and dead bodies in varying states of decay. Guests step through a dead street, where survivors wearing gas masks and ugly sweaters intimidate guests. The next room is an abandoned shopping mall, where guests have to deal with aggressive mutant shoppers, and a giant mutant Mall Santa. The third room has guests walk through an abandoned, ruined home, where some psycho survivors attack. A blue mutant covered in ice will burst through a window, and a scavenger in a Santa suit will burst out of the chimney, wielding a shotgun. The music video will play on loop on a TV. As guests exit the scene, a group of carolers in gas masks greet guests, and Weird Al will break from the crowd and scare guests. (Apocalypse)
Father Christmas: Guests walk up to a department store. In front, kids attack a mall Santa, occasionally turning to guests. Inside, more offbrand Schittie's Kids. Some hide in the shelves, on displays, some just run over from other aisles. A kid pops out of a towel display, a kid hides in a stuffed bear, Uter's in the candy, the workers are being terrorized. Near the end, an older kid bursts out with a toy machine gun. (Anarchy)
Zombie Christmas: Guests enter a house decorated for Christmas, in the living room, where a zombie drops out of the chimney. The next scene is the suburban street, where zombies are tripping over decorations in their attempts to get to your flesh. As guest dart into the woods behind the houses, a zombie pops out of the picket fence. In the woods, zombies and hunters clash. Constant gunfire, moaning, and at least one guy being attacked by zombies. (Zombies)
Monster's Holiday: Guests enter the castle from Monster Mash, including the banquet hall with a Christmas overlay. The castle is in color, and guests are still avoiding the monsters. However, guest then walk past a hall full of monsters, where you can here Dracula planning to rob Santa's Sleigh. The last scene is the rooftop, where Santa is on top of the sleigh, fending off zombies. As guests transition into the final scene, Frankenstein's monster rides up on a tricycle, out of the darkness. It's not really a scare, but a "What the heck?". (Monsters. In a normal Monster Music, it'd be first, but it's also the least violent of the five songs.)
The Night Santa Went Crazy: Guests walk in through an abandoned Santa's Workshop, where everything is broken. Santa Claus will kick down the door and fire an AK at guests. As guests go through the abandoned workshop, dead elves and reindeer are abundant, and Claus will burst out with a number of weapons (an old German Luger, a Freddy Glove, the like. There's a lot of good instruments of murder). As guests go outside, they see the charred remains of Blitzen, accompanied by a Flamethrower-wielding Saint Nick, and military vehicles lit by searchlights. The final scene changes with the cast. One scene has Santa in prison, where he will bend the bars and chase after guests. The second is the Extra-Gory version, where Santa Claus's headless corpse lies on the floor. (If you're asking how a headshot can take off a head, see Meet The Spy.) The headless Santa will chase after guests.
Finale: The music matches that of the queue line, and guests walk through a normal, festive living room. Well, Festive aside from characters from the songs attacking. A kid throws a tantrum by the tree, a mutant will tear through the wall, a zombie breaks through the window, and Santa Claus will crawl through the chimney. As guests exit the house, Igor will run up to them.
QUEUE LINE MUSIC SUGGESTIONS:
Carol of The Bells - Manheim Steam Roller
Christmas in Hollis - RUN-DMC
Perfect Christmas Night / Grinch - Trans-Siberian Orchestra
Snoopy's Christmas - The Royal Guardsmen
You're A Mean One, Mr. Grinch - Thurl Rovenscroft
Run Run Rudolph - Chuck Berry
Christmas Wrapping - The Waitresses
Blue Christmas - Elvis Presley
Last Christmas - The Living Tombstone
I Am Santa Claus - Bob Rivers
Oh Little Town of Bethlehem - Bob Rivers
Wizards in Winter - Trans-Siberian Orchestra