Last year I started working on a Christmas/Holiday themed adventure and I finally got a moment to get back to it again this last week. While I haven't developed out the adventure too much more, I got in the holiday spirit and started considering what characters could be used as NPCs or PCs if you wanted to hand out characters. I started going through the iconic Christmas characters and determined the best classes for them and some basic features they may have. I admit they're not perfect, but it's surprising how easily some of these characters fit. I haven't decided on levels yet, but since a couple are prestige classes it's assumed that each character is at least level 7.
Herbie (from "Rudolph the Red-Nosed Reindeer")
Elf Druid with a Reindeer companion Rudolph.
Yukon Cornelius (from "Rudolph the Red-Nosed Reindeer")
Dwarf/Human Fighter
Heat Miser (from "A Year Without A Santa Claus")
Half-Orge Pyrokineticist (He's only a half-ogre based on his wikipedia article that refers to him as "...an ogre or demon-like being...")
Snow Miser (from "A Year Without A Santa Claus")
Human Cryokineticist (Not technically a class, but presumably changing any fire effects to ice effects should suffice)
The Grinch (from "How The Grinch Stole Christmas")
Killoren Barbarian
Buddy the Elf (from "Elf")
Elf Bard
Bob Cratchet (from "A Christmas Carol")
Human Human Paragon
Jack Frost (from "Jack Frost" (1979))
Ice Genasi Wizard
There are definitely more that I haven't listed above, but this is just a sample of what could possibly be added to the story. At the same time though, there are definitely characters that I have intentionally omitted because they have been included in other parts of the adventure. For example, you may have noticed a distinct lack of a jolly gentlemen, often seen in a red suit with reindeer. With my current plans, said character will most definitely show up at some point.
I hope to have a portion of this adventure ready to go by Christmastime and perhaps if I feel it's strong enough I'll release it in portions or in its entirety here, but only time will tell.