I'm posting this a bit late after the holidays have ended, but looking back my Christmas Truce 2017 fic wasn't absolutely terrible so I figured I may as well upload it onto ffn and ao3 in case other people are interested in reading it. I don't have any plans at continuing this fic (and my life is already too busy to continue the ones I'd like to) but I am open as always to discussing headcanons about the fic and having someone else continue it if there's interest! I personally love the headcanon of Danny's ghost half parasitically feeding on his obsession, so this was a ton of fun to imagine and hopefully is also a good read.

allhailthedramallama asked for "Anything with Tucker/Danny (romantic or platonic, both is fine) would make my day. Also if ghostly Santa feels comfortable with doing something angsty/vaguely horroresque my favorite headcanon is the one where Danny's ghost half needs some sort of ghostly sustenance (ectoplasm, human emotions, things like that). So if they'd like to do something with that I'd be happy too."

Enjoy!

"Hey guys, sorry I'm late! Jazz is going on one of her OCD test anxiety freakouts and somehow convinced my mom that what we need to do is have sit down breakfasts like a normal family."

Both Sam and Tucker were used to their best friend popping up out of literal thin air to flinch when Danny phased onto the couch in Sam's basement and reached out to grab the waiting videogame controller. In fact, neither teenager gave Danny more than a wave over their shoulder as Tucker hooked up the new YBox 720 to Sam's ridiculously large TV and Sam flipped through Vampire Hunters' instruction manual.

"Oh wow, that reminds me of when my Mom tried to start every day with sunny-side-up eggs and bacon smiley faces. It took two weeks of daily powerpoints and an occult ritual to get her to realize I might have a problem with the bacon, and you know what she does? Switches to Canadian bacon instead, like that makes it any better!"

"Hey," Tucker cut in, "We all know everything's more humane in Canada."

Sam shot him a deadpan glare and twitched her steel-toed boot threateningly.

"But seriously Sam, two weeks of bacon and you couldn't bother to bring any of it to your favorite meat connoisseur Tucker Foley? It's not like it makes a difference to the pig once it's already been cooked!"

Sam bristled and dropped the instruction book beside her. "Oh really Tucker, you want to go there? Fine!"

"Guys!" Danny cut in, leaning back into the couch between his two friends as if he could get out of the way of another one of their infamous fights. "Can we please just skip it today and leave the fighting to the Vampire Hunters? Remember, all-day Saturday videogame marathon on a TV so big our characters are actually life-sized?!"

Luckily, both Sam and Tucker backed down. Sam even looked a little sheepish after Danny's scolding.

"Yeah, sorry about that dude." Tucker apologized. "I almost got the YBox set up and then we should be good to go. So, you ready to bow down to King Tuck at... Dude! What happened to you?!"

And with that comment both Sam and Tucker turned to take in their best friend for the first time that morning. Danny's arm was draped back and loose with exhaustion over eyes that were sunken and dull. His hair, normally the raven black that Sam's dye tried to emulate was a coal grey, and hung limply on skin whiter than his typical tee shirt.

"What happened to me? Gee I don't know. I woke up this morning after spending half the night patrolling and capturing the Box Ghost twice, had a surprise family breakfast cut in to an all-day videogame marathon that's the one thing I've been looking forward to all week, had to eat my mom's cooking, and now I get here and my two best friends can't stop fighting before we even start!" Even just cocking his eyebrow to give Tucker a sarcastic look appeared to take effort, but Danny didn't let it lessen his snark.

"Danny," Sam started, "About the marathon…"

"Hey?" Tucker cut in, "Are we seriously going to start ignoring Danny's condition right now? I hate to say it dude, but you look like you saw a ghost."

"Thanks Tucker. I was pretty sure I looked in a mirror this morning, but your confirmation is reassuring."

"I know I never say this Danny, but Tucker's right." Sam crossed over to Danny and put her hand on his forehead. "You look more goth than even I'm comfortable with, and it's been getting worse ever since the accident. Maybe we should just give our game day a rain check and you can take a nap here or something."

"Inviting Danny to sleep over in your house already, Sam? Man, that's forward!"

Both Sam and Danny simultaneously blushed. "Shut up Tucker!"

Tucker chuckled, "Still got it.

"But seriously Danny, you look about ready to die again, and you've been getting worse all week. Which got me thinking that maybe it's not just sleep deprivation or your mom's cooking." Tucker stood back from Sam's TV and YBox with a quick proud grin before turning back to his best friends.

"I mean, I've been uploading the information we have on Danny's ghost fights into a new database and it got me thinking. Every major ghost Danny's fought so far has some emotion or obsession that makes them stronger, and they seem almost powerless without it. Lunch Lady had the usual menu, those dragon amulets needed rage and jealousy, Skulker has his hunting, and Technus was even more obsessed with beautiful technology than I am!"

Sam sent Tucker an appraising look. "Ok, that makes some sense. What's your point?"

"I'm thinking that if Danny has an obsession that he isn't fulfilling or something, maybe that's why he's looking so sick! It isn't a problem with his human half…"

"It's a problem with his ghost half!" Sam finished for him. "Tucker, you're a genius!"

"I know, no need to thank me. Your continued adoration is payment enough."

Sam grimaced. "Ignoring that last comment, let's say Danny's condition is because of a problem with his ghost half. What are we supposed to do about it?"

"Simple," Tucker said. "We figure out what Danny's obsession is and top him up the best we can on it!"

Danny reached forward to grab the game controller in front of him. "Guys, I'm fine, let's just have some fun and kill vampires, okay?"

Sam and Tucker both stared at Danny, who was already slumping back into the couch. Then the two human best friends looked back at each other. "So, Tucker, any ideas what the obsession might be?"

"I've got a working list on my PDA and have been updating it all week. Just crossed off home-cooked breakfasts."

"Alright let's head out and start at the top."

"Sam, Tucker, can we please just forget about my ghost half for one day and have some fun playing videogames for the afternoon?"

Sam openly winced this time. "Danny, about the videogame marathon…"

"Oh Sammykins!" The unmistakable sound of Pamela Manson's voice echoed down from above the basement stairwell and Danny leapt behind the couch to hide. Luckily for the three teens Sam's parents never deigned to come down into the million-dollar basement they designed for their daughter, meaning no questions were raised as to how another teenager suddenly appeared without coming through the door.

"It's almost time to get dressed for the gala in Gotham City tonight! The private jet's leaving in an hour!"

Danny turned to look at Sam, only to find the girl staring back at him, but quickly breaking eye contact to look down at her boots.

"I've been trying to get out of it for weeks, and then today I was hoping we'd have time for at least a game or two but then you were late, and… I'm sorry guys, maybe some other time?"

Danny looked over at Sam and sighed, rubbing his hand on the back of his neck. "Yeah Sam, next weekend sounds fine."

Sam started towards the stairs while Danny and Tucker sat unmoving on the couch. A second later she paused and the three teens shared a look.

"You know Grandma Ida doesn't do well on the private jet so you can't just haunt my basement and play Vampire Hunters without me, right?"

Danny and Tucker threw their arms up.

"Come on, Sam! Now what are we supposed to do all afternoon?"

Sam sighed. "I know this would probably go better with both me and Tucker helping, but you probably should probably start trying to figure out what's wrong with your ghost half."

Danny let out a groan. "There's nothing wrong with my ghost half!"

Sam sent him a look. "Tucker, is abject denial on your list of symptoms?"

"Right at the top. I got a list of both potential obsessions and symptoms. They're alphabetized."

Danny looked between his two traitorous best friends. "Sam, Tucker, how many times do I have to say that I'm fine?!"

"Until you stop looking more like a vampire than I do, Danny." Sam dragged/assisted Danny off the couch and pushed him over to Tucker. "Do you think the two of you will be fine on your own?"

Tucker grinned. "Me and Danny? Puh-lease. I've been his best friend since we were five, I'm pretty sure I know him better than anyone in this room!"

Danny shot Tucker a glare from under his now outstretch arm. "Um hello? I'm right here!"

Tucker glanced down at Danny, before looking over at Sam, raising his eyebrows flirtatiously, then smiling back at his clueless friend. "I rest my case."

If anyone had left the afternoon football game at Casper High halfway through the third quarter they might have seen Danny Fenton and Tucker Foley appear out of midair by the locker room exit. Even without the sudden phasing into existing Danny Fenton was pale enough to easily pass for a ghost, and Tucker Foley could also pass for possessed given the fifteen whole seconds it took for him to pull out his PDA.

"Well, that was entertaining." Tucker said after a second, typing his experiences into his electronic journal as Danny stood there rubbing his cheek.

Tucker finished his work and looked up. "You okay, dude?"

"I've never been punched by a pom-pom while intangible before. It felt weird."

"And I've never been invisibly pulled into the girl's locker room before, which is outrageous given that it's been what, three months since you got ghost powers?! Sheesh, man, share the love."

"Come on, Tucker! It was a pom-pom and I was intangible, how was I even able to feel that?!"

Tucker sighed and started walking down the street back towards town. "Well, you focusing on pom-poms rather than Paulina crosses cheerleaders off our list. Seriously dude, you realize you can feel cheerleaders while invisible and intangible and stop at pom-pom?"

Danny paused mid-step after Tucker to smack himself in the face. "Ugh, way to go Fenton."

Tucker just laughed. "And I'm pretty sure Paulina can also be crossed off the list! That's two items down and a couple dozen more to go! Next up is the Amity Park arcade to check out some of those latest videogames!"

"Is this supposed to be a list of my obsessions, or yours?"

Tucker just grinned. "Two birds with one stone, right? We both get to try to make you feel better and get to have a day of fun just the two of us! Sound good?"

Danny shrugged. "Fine by me. But if we're really going to check off things I like, let's go down to the Science and Space Museum, they have a whole exhibit on rockets."

"Dannnny…"

The half-teen grabbed Tucker's hand and started pulling him in the direction of the space museum. "Rockets and the computer technology that help launch them."

"You had me at 'technology!'"

"Okay, no matter how much you kept fawning over that old NASA spacesuit-"

"Tucker, it was the actual spacesuit worn by Neil Armstrong!"

"-and while you sound a little better, you still got confused for a mannequin by one of the tour guides, so I'm gonna go ahead and check off space travel as not being your secret ghostly obsession."

Danny sighed and rubbed at the bags still under his eyes. "Fine, what's next?"

Tucker grinned. "So glad you asked, because next is me certainly not letting you weasel your way out of a ghost-powered trip to the arcade!"

"Tucker, was it really such a good idea to have me phase tokens out of the coin machine? I'm pretty sure that's stealing."

"Lighten up dude, the only stealing in there is how many tickets they charge for one of those lava lamps! Not to mention we got to play almost an hour of the latest VR Doom for free before we had to make a break for it!"

"We almost got banned for life, Tuck."

"Key word is almost, my friend. And you still look like a walking game over, somehow a little worse than before, so I'm crossing video games off the list."

"Can we not just blatantly take advantage of my ghost powers for the next one?"

Tucker sighed. "Sure thing, dude. The Vampire Hunter movie tying in with the video game just hit theaters, and I think I have enough allowance money to pay for tickets. Let's go see if vampires, zombies, or random Abraham Lincoln cameos charge you back up?"

"You seriously put Abraham Lincoln on your list?" Danny shot Tucker and glare and tried to snatch the PDA out of his hand before Tucker twisted away.

"Hey, dude, you're not allowed to see the list! And yeah, I may have added a couple of fun ones in just so I could cross them off later!"

"Give me that!"

The two teens ran halfway across Amity Park to reach the theater. And while Danny may have never caught up to Tucker to steal the techno-geek's PDA, the human-form ghost boy was laughing and hardly winded by the time the movie started.

"Man, that movie was great! And you know that the best part was? A crowded, sold-out movie theater showing a horror flick and not a single ghost attack the entire time! Can you believe it Tucker?"

"Yeah," Tucker replied, stretching and rubbing his eyes as he pulled out his PDA to cross the latest set of items off the list automatically. "Though I guess it could've used a couple fewer jump scares. They're cheap horror for this caliber movie and leave me feeling a bit twitchy afterwards. If I wanted bad special effects in my face I would've gone to see Cyber Zombie Commando."

Danny shot Tucker a smile. "I know, you can do better. What's next?"

"Dumpty Humpty just dropped a new single that should be over at Amity Records? Wanna go see if music recharges your ghost half?"

"As long as it isn't Ember, I'm in." Danny quipped. "But hey, doesn't Amity Records only have one set of headphones to listen to samples? I kinda spent the last of my cash on Vampire Hunters and Sam isn't here to buy us half the store."

Tucker shrugged. "I just figured I'd listen to it online later. Besides, it's your obsession we're trying to figure out."

"Hey, Tucker?"

"What is it, Danny?"

"Thanks."

"Anytime."

"Wow! That new single was awesome! Hey, Tucker, are you sure you don't want a turn?"

Tucker shook his head with a considerable effort and pushed off the rack of CDs he was leaning against. "Nah man, I'm cool. You're looking a bit better so I'm gonna mark down music and Dumpty Humpty as maybes."

Danny reached out to catch Tucker as he started swaying. "Woah! I don't know if I'm feeling all that better but you're certainly getting worse! I've had a ton of fun so how about we just call it a day?"

Tucker looked up at his friend and gave a small smile. "Sorry, bro, no can do. If we don't figure out exactly what it is that's helping, how are we supposed to keep your ghost half from getting sick again? Let's just keep going."

Danny tried to think of a way to talk Tucker out of it before sighing. "Fine, you've got a point. But whatever the next thing we're doing on your list better be something where we can sit down and get you back on your game. Isn't the Nasty Burger or something on there?"

"I think so, yeah."

"Then let's go, we can split two of the Carnivore's Supreme with Nasty Shakes."

"Dude, it only counts for the list if we test your favorite."

Danny slurped up the last of his vanilla milkshake before leaning over at Tucker who was almost sprawled across the booth. "You didn't even finish the meat on your burger? And you ordered the same single patty I did? Tucker, something's definitely wrong!"

Tucker's eyes looked slightly glazed as he smiled up at Danny. "Don't worry about me, I'm fine. And I'm glad to see you're looking almost completely better. Guess the next step now is to narrow it down to things already on the list…"

Danny's arm darted across the table and knocked Tucker's PDA out of his hand and onto the floor. "Enough about that stupid list! Tucker, you look exhausted, you're not eating meat that's right in front of you, and you can barely sit up straight, I'm worried about you! We can look more into my weird ghost half symptoms later, right now I want to focus on what human stuff is wrong with you!"

Tucker sighed. "Alright, just give me a minute to find a diagnosis on my PDA. I'm sure it's just a cold or something."

Danny passed Tucker's PDA back to him before settling in the booth. "Alright, tell me what you got, Tucker."

"Just give me a second, Danny. Perfection takes time."

"Tucker…

"Tucker, it's been a minute and you don't have answers.

"Tucker, your hands are shaking so bad you can barely type! Come on, we're going to the library!"

Tucker tried to push back against Danny dragging him out of the Nasty Burger, but the gesture fell short before he could even make contact with half-ghost teen. Danny shot Tucker a worried looking before going ghost and flying his best friend towards the familiar building.

"Seriously Danny, we don't need to go to a library when I have all the answers on the go!"

"We're already in the air, Tuck. It's the library or the hospital."

"Fine. Library it is."

"Well, I wasn't expecting to see you here on a Saturday, whelp. But I guess this only makes it easier for me finally catch your pelt and hang it on my wall!"

Danny let out a groan as Skulker flew down from who knows where while he was scanning the shelves for anything that might have an answer to why Tucker was suddenly clammy and pale as a ghost (all the multi-colored Ghost Zone residents aside). Tucker himself was resting at one of the reading tables just a few feet away, looking barely conscious as he watched his friend angrily flip through book after book and trying hopelessly to type something on his PDA.

"I don't have time for this, Skulker! Wait, what are you doing at the Amity Park library on a Saturday afternoon anyway?"

Skulker just glared. "I happen to be here checking out a book on purple-backed gorillas for the 23rd time this week, thanks to you. Which begs the question as to why you happened to walk into the trap you made for me, unless you've decided to simply give up and hand over your pelt to me?"

"Not a chance! It's just… something weird was going on with my ghost half all day and now Tucker's suddenly getting really sick. I'm trying to find out if there's anything I can do but there's nothing relevant in any of these useless books!"

"You really don't know, whelp?"

Danny looked up at the pensive ghost hunter, "know what?"

Skulker just ignored him to look over at Tucker. "Hmm… If you really don't yet know what your obsession is, then telling you could give you a tactical advantage. But never let it be said that the Ghost Zone's Greatest Hunter took down easy prey. That, and existential horror would make a fitting final expression for your pelt when I hang it above my mantle. Fine, whelp, I'll tell you what your obsession is, and why your human friend is growing weaker."

Danny paused. "What are you talking about?"

Skulker chuckled. "You haven't figured it out yet, whelp? All ghosts are obsessive by nature, it's how we cling to existence and what makes us unique. Your unique obsession is what makes you such valuable and elusive prey, and is why I will have your hide eventually."

"I thought you wanted to hunt me because I'm half ghost?"

The ghost hunter nodded. "And don't you understand that to ghosts, the two statements are exactly the same? You are unique among our kind because your are alive. You still have human friends, human emotions, human life, and likewise your obsession is life itself. As long as you can keep living and creating new human relationships you will be one of the strongest specimen in the Ghost Zone, because as long as are able to form emotional human alliances you can find new sources of power to care all of those selfless, un-obsessive human emotions about you and keep draining the old ones dry.

"Do you think it's easy always tracking down the strongest, fastest, most elusive prey in the Ghost Zone, just to hold on to existence? Do you think that Ember has a simple time gathering millions of fans each time she enters the human world, or that Technus was encode a version of himself that could upload to any generation of technology on the first try? Most ghosts pour our entire existences into our obsessions just to get by, because even the whole world at our fingers is never enough, but for you satiation is as easy as breathing. You are unique, whelp, because you don't need the whole human world worshipping your heroic deeds to restore your ghost powers when you run dry, you just need one.

"And that's why I'll be coming for you, whelp, along with every other ghost and hunter in the Ghost Zone. Because maybe that ability to finally find rest will pass on through your hide once it's hanging in my lair. Until then, I have to go check out yet another book on purple backed gorillas." Skulker's wings popped out and started blasting him towards reception, but the ghost pointed one last finger over towards Tucker.

"Happy hunting."

Danny gaped after Skulker until the ghost was out of sight before dashing over towards Tucker, whose head was resting on the table and a bad enough angle that Danny's heart skipped a beat at the thought that his friend passed out before seeing Tucker's blurry eyes open in his direction.

"Hey Danny."

"Tucker, are you alright? Did you hear all of that just now?"

"Yeah dude, I'm fine. I'm glad we finally pinned down what was making you feel better now. Though I gotta admit I feel kinda stupid."

Danny blinked. "What do you mean, Tucker?"

"Well, I put down Sam, Paulina, hell even Abraham Lincoln, and I can't believe I forgot to put Too Fine Tucker Foley as an option on my list."

"Come on Tucker, is now really the time to be joking about that?"

"Not much else I can do without making you feel worse again. Just, be sure to tell everything to Sam so she's up to speed before it gets to her."

"It isn't going to get to her, Tucker! Damn it I'm not about to let any of my ghost powers get to you!"

"No, it's alright Danny. My goals were to have fun and make you feel better and I got to do both of them. I'm happy. Just one last thing…"

"What is it?"

"For the record… I don't blame you."