A/N: This is the first story I've ever bothered to finish, probably due to the extreme Christmas spirit I felt while writing this. Also it's almost midnight, and I just finished so please excuse any continuity errors or oddness in general (I'll review this in the morning). There wasn't really a set season this would take place, but probably sometime around/after season 5 since Cas and Dean are actually friends?
Based off this tumblr post: t-a-r-d-i-spacethefinalfrontier . tumblr post/71084655889
"Dean, wake up."
Dean grunted and rolled over, dragging the covers over his shoulder and trying to burrow deeper into the shitty motel bed. Damn, this mattress refused to keep in any heat in the cold Colorado winter.
"Dean!" This Dean felt the covers being pulled off him and tossed away, and he groaned, mumbling curses incoherently at Sam who stood at the foot of the bed impatiently.
"What the hell, Sammy? Can't let a man sleep on Christmas Eve?" He swung his legs over the edge of the bed and stood up, rubbing the sleep from his eyes and stretching. Dean ran his hand tiredly over the back of his neck as he headed for the pot of coffee on the kitchenette counter.
"It's hardly Christmas Eve, man; it's only 9 AM." Sam said, sliding into the table chair and typing something into the search bar. "And do you really have to make that sound? It's gross."
Dean poured himself a steaming mug of black coffee and slurped it loudly, smirking at Sam's annoyed bitch face over the rim. He pulled out a chair at the table as well and rested his head on his forearms as Sam continued to click-clack away.
Sam turned the computer screen around so Dean could see. "So get this. You know that Christmas song 'Grandma Got Run Over by a Reindeer'? Well a couple days ago, an old lady and her husband were driving to their son's house for the holidays when the husband hit something big in the snowstorm. The wife got out of the car to go see what it was, and then the husband heard her scream and a lot of noise. So he gets out of the car too and finds her basically trampled into the snow with hoof prints all around and over her, but none leading away." He clicked through the photos of the accident and the police report, as well as an animal expert's bemused confirmation that the tracks were definitely reindeer.
Dean grunted, "So? The expert could be wrong; people hit animals all the time, and moose aren't exactly the friendliest when you piss them off—believe me. Heh, remember that time when we were holed up in Montana and I went outside to chop firewood and I accidentally got between a momma and her baby moose? Man, that was scary as hell, zero out of ten, would not recommend."
"No, this happened here in Colorado. There are no reindeer this far south, Dean. Doesn't that strike you as a little odd?" Sam interrupted, pulling up a map of reindeer migration patterns. He was right, Dean noted. Canada was about as far as reindeer went.
"Yeah, but this one time doesn't exactly mean much. It could be a fluke or something weird like that." He sat back in his seat, downing the rest of the coffee.
More windows were pulled up on the screen, each from a different year, but with a similar headline of 'Grandparent/Woman/Man/Teenager Killed in Deer Accident.' Dean tugged the laptop closer in a sudden rise of interest. "See, I thought you would say that, so I took the initiative to see if anything like this has happened before, and I was right. The farthest case back I could find was in 1982. It was pretty quiet for almost a decade after that, mostly sporadic killings, but it happened again in '92; then it became a seasonal thing after '98. Every time around Christmas Eve, someone would be killed by a 'small moose' that had no tracks leading away," Sam explained, pointing at each of the case files. He finished, looking up at Dean to validate his hunch. "Look, I know it's not much to go on, but we're not exactly doing anything this Christmas, so why don't we go check it out since it's not that far?"
"Fine, Sammy," Dean sighed as he stood up to go pack the duffel to toss in the Impala. He turned and pointed an emphatic finger at his brother. "But I expect a damn good present!"
Sam laughed and shook his head, "Alright, Dean," and headed to pack up what he had as well.