In honor of Delta's birthday, I have a list of 50 of my headcanons for him! Enjoy :3
- They REALLY likes soft/warm things. They have so many blankets in their room. They might even have some kind of heat lamp in their room for the colder months (he shares it with Epic and Color, ofc).
- They don't like storms, but can put up with rain. Rain just makes Beta a bit concerned.
- Delta likes ghost hunting! His version is just going to abandoned/haunted places and learning about the ghosts there. Usually Epic and Color come along. A lot of chaos usually ensues.
- They don't fuck with demons if they can help it. Other ghosts are fine (if Beta's alright with them), but demons are not to be interacted with.
- Delta is immune to driving a normal car. It's either a motorcycle or a truck, or nothing at all. He's also the only one of the Epic Sanses who can probably legally drive (as long as Beta's not in control of the body).
- They don't like loud noises or flashing lights. It's too overstimulating. Bright things, they're okay with. The only loud noises they can really tolerate is music.
- His gauntlets act kinda like slatemail when it comes to coming into contact with a sharp weapon, and they also do great with blunt weapons.
- He has phantom pain from getting cut in half. Sometimes the pain activates as a warning to slow down, or may pass as a "gut feeling"/instinct about something. But to aid that pain (and protect the area from further harm), he wears an adjustable metal/slatemail corset underneath his sweater. There's a soft fabric over the metal for comfort, of course. It acts like a brace to keep them feeling stable.
- They have some medical knowledge. Most of it is what they consider "battlefield" stuff; how to wrap a tourniquet, how to apply splints, making sure someone can breathe if they're unconscious, putting in an IV, how to carry someone safely when they're injured, how to stop bleeding, how to use an NPA/OPA, etc. But the rest of their medical knowledge comes from Color and whatever memories Beta has!
- The reason Color is involved in their medical knowledge is because 1. When Color was still pretty fresh out of the VOID, Delta had to learn how to take care of them and adjust his life and apartment for them. And 2. I agree with the headcanon (I think by Howls?) that Color hyperfocused on learning medical knowledge so he could help himself and others.
- And the reason Beta is involved is because both Howls and I have agreed that at least one person in Beta's past family (like before he fell) was a nurse or doctor. Probably his mother, I'd assume.
- They can negotiate. They're pretty good at it, actually. Their negotiations just involve a lot of threats and blackmail. So it works, and that's all that matters to them.
- Speaking of blackmail! They have a shitload of it. Beta being a ghost means that he could possibly alter or impact technology, like cameras or voice recorders, so he'd be the one usually getting the info by listening in (he's also invisible to those that can't see ghosts, obviously). And Sans likes keeping tabs on people so they're both up to date on what's going on in their friend's lives.
- Their recklessness is always calculated. It may not look like it in the moment, but it is. Unfortunately, it's really only calculated in a way they understand.
- There are very few times when Delta wouldn't be the one to start the fight. But if kids are around, or there are cameras that Beta can't get rid of, they will avoid a fight at all costs. If one still occurs, they will play defense and try to isolate their attacker to make sure very few people see. They don't want any witnesses, and they especially don't want any other kids seeing it.
- He's pretty decent with kids, but better with older ones. He doesn't really know what to do with the younger ones, or at least kids who are a couple years younger than Beta. However, if he was stuck with someone else's kid for an extended period of time, that child would come out knowing how to square up and throw hands properly for their age. If you're not ready for that, then either tell him so or don't leave him alone with your kid for an extended period of time.
- Delta's actually fairly friendly when not fighting! Of course, if you approach at random, his first instinct is to figure out if you're going to try to fight him or his friends. But if you're not, he'll relax.
- They're a little directionally challenged. Even with practice, they still struggle with getting to the right AU when they're working. But aside from AU hopping, they're just overall directionally challenged in the OT, too. Mostly because of their ADHD (they get distracted, or forget where they were going and why).
- He forgets things. A lot. Especially when stressed or distracted. He has reminders and notes on important things, such as birthdays or events, but smaller stuff can get easily forgotten. Along with that, time blindness! Without a clock it's hard to figure out how much time has passed when he's doing something, especially if he's hyperfocused or in a fight.
- Someone (I think Zu?) made a headcanon about how the Bravery trait is explosive. I took a bit of a different turn on it. When Beta gets too emotional (angry, excited, scared, pretty much any emotion), his skin starts to look like it's jumping, kinda like fireworks, which is his warning to calm down. If he doesn't calm down, he will "explode" into energy, and go right back to Delta's side (like a spawn point) if he was away from Delta. It doesn't really matter how far from Delta he was, he'll just end up right back there.
- Along with that, when Delta gets too emotional (again, any emotion), they start to have a physical, burning glow. The brighter it gets, the hotter it is. Beta's "explosions" don't really have a massive impact on it if he's out of the body. But if he's in the body, it can start the glow.
- His ass canNOT be trusted in the kitchen. He cooks well, but forgets what he's doing and gets distracted. The food eventually gets burned. He is also the type to microwave a grape just to see what happens (Epic probably asked and gave Delta the idea). But when they're able to actually focus, the food usually turns out pretty good!
- Don't give them anything with fire, especially a flamethrower. If you do, prepare to call the fire department, because something will go up in flames.
- Aroace biromantic. NOW HEAR ME OUT. We all know that man is somewhere on the aro/ace spectrum, if not both. I think he's both. The biromantic part comes from the idea that OG Undertale Sans (and Deltarune) has been interpreted to have a crush on Toriel. Therefore, Sans (Delta) has possibly experienced that kind of attraction before. Along with that, he lives with Epic and Color now, which some interpret as the three being poly or a qpr or other things, if not just friends and teammates (I personally don't have a strong opinion for or against these opinions, so do what you will). So therefore, biromantic.
- I think he might also be very closeted in regards to his sexuality, with only his closest friends knowing (it's just not something people really need to know, because he simply does not give a fuck about what they think of him, but he doesn't want to give them any ammo).
- And okay listen I agree on him having some very internalized toxic masculinity. BUT. I can also see that if for whatever reason one of his friends wanted to wear a dress/skirt/makeup/whatever, but they were afraid to do it alone... Delta would offer to do it with them. Yes, he cares about manliness, but ain't nothing more manly than showing up for your friends and making them feel happy and confident. Would he like it? No, probably not. But he'd do it.
- He talks outta pocket a bit too much. Especially if Beta's around to influence or take control. However, they're not skilled at hurting feelings - they'd rather just wreck someone's shit. And they don't often get their feelings hurt in return, because they don't give the enemy enough to talk shit about.
- They have so much attitude. Most of the time it's unintentional (unless you pissed them off) or just casual sass/sarcasm. They often get petty to get right with someone who inconvenienced them, but will also confront them directly before doing so. They can also be a bit dramatic at times.
- He has a scary RBF. It's an unintentional way of warning people to not fuck with him, or anyone he's with. He's not entirely aware of it.
- They swear a lot. They try to dial it down in public, though. There are plenty of people who could get scared by their unintentional aggression, and they don't want that.
- They have killed for themselves and their loved ones, and they will do it again with no hesitation (unless there's witnesses). They don't play.
- I think Howls is the one that made the headcanon that Delta works in a mechanic shop? Anyways I think bro works there just to have something to do. He loves working with his hands, especially if he gets to either be on his own or teach others. I think they'd probably mentor a lot of the new hires.
- He doesn't really know what to do with affection, especially the physical kind. He's not used to giving or receiving it. It feels kind of uncomfortable, especially after fighting someone. I think they'd get more used to it the longer they're around Epic and Color, but they're still better at giving the affection than getting it.
- They adapt quickly to new circumstances and situations. Do they like these new things? No, probably not. But they can cope long enough to withstand it to leave said new things.
- They're really good at lying. Concerningly good at it. They don't really have a "tell" when they lie, or a certain demeanor change. Only Color, Epic and Zorox are able to clock it (and sometimes they miss it) because they recognize there's a tiny shift, and they know something's off.
- Delta hides his emotions a lot. Usually, their demeanor stays serious and confident when out doing random things. They don't want to seem "weak" in public, especially during fights. He's able to relax a bit at work, but at home is where he feels safe to actually relax. There are times when he still tries to hide his emotions from Epic and Color, though. But they clock it if Zorox doesn't call Delta out first.
- He puts Beta and/or Zorox in "air jail" when they're misbehaving too much. He does this using magic. Beta finds it more funny than punishing. Zorox gets out faster than Beta does.
- The safest way to stop Delta from fighting is to physically get between them and their opponent, and to not let up until they back down. The only physically restraining method that would work is if Color scruffs him by the back of his sweater like a cat (I'd imagine Color does this more as a warning than an actual restraint method, though). Zorox's method of stopping him is biting the end of his shirt or pants to hold him back, or running in front of him and jumping up so Delta can't see his opponent.
- They have a soft spot for animals. That came from Zorox and the other animals the group has (Epic has Toby, Color has his sugar gliders (I forgot who headcannoned that, sorry 🙏)), but especially Zorox.
- Delta can tolerate bugs and insects, but would prefer to stay away from them. Beta doesn't like cockroaches or spiders, though. He won't completely freak out if he sees one, but he's definetly going to kill it. He'll only freak out if one touches him.
- He's the youngest of the group! Based on how he acts, most people outside of the group wouldn't see how. But when you pay closer attention to how he acts around his friends, it makes more sense.
- He doesn't like to use his ecto-body because it might give the enemy an easier time landing hits. Plus, it's not like anyone is really gonna see it. However, if they're in a fight and they're trying to protect or shield someone, they will activate their ecto-body. This is so if the enemy sends an attack, it'll hit Delta and not the other person.
- He loooves going on long walks with Zorox. It means they get to wander and be lost for hours and no one can really question them about it. They also take pictures of the scenery for Color. Sometimes Epic and Color tag along, and both Delta and Zorox love that, too.
- They like going to libraries, and are usually silent when in there. Especially if they're fixated on what they're reading. It's like a safe space for them both.
- They talk to themselves a lot. Whether it's during a dissociation episode or while they're trying to figure out some kind of problem, they'll just quietly talk. Beta's voice and Sans's voice have somewhat clear distinctions - Beta sounds a little higher in pitch with a Filipino accent, Sans sounds tired with a slight accent. Delta's normal voice is a mix of Sans and Beta's voices. Color, Epic and Zorox can differentiate the voices between the two.
- I think they'd actually get along okay with humans in the OT, as long as the humans don't cause any trouble.
- I agree with the headcanon from Toffee (and Howls?) about the Epic Sanses having friendship bracelets! Specifically, I think Delta has 3 - one for Delta, one for Sans, and one for Beta. They also probably made an animal-safe version of a friendship bracelet for Zorox, too!
- When Beta's out of the body, and Delta's with someone who might need a little "encouragement" (aka; "this person need to grow a backbone and defend themselves because we wont always be around to do it for them"), Beta can give them that encouragement. He does this by physically interacting with the person (usually he just grabs their shoulders), and his energy rubs off on them. It gives the person a sudden burst of energy, and the sudden bravery to do what needs to be done. It wears off hard. I call them "Bravery shots" (I thought it sounded cool).
- If the Epic Sanses go on a mission and kids are involved, they'll all take roles in taking care of them. Delta's role is reassuring and protecting them. Usually Beta is incredibly present when this occurs (if he's not already co-fronting) and helps guide Sans/Delta on what to say or how to help best. He's not the best at comfort (he's scared of accidentally fucking up and scaring the kid), so he leaves that to Epic and Color.
- And finally: their eyes change color depending on who's present/fronting! I drew some pictures to demonstrate :D
When Sans is fronting:
When Beta is present, but Sans is fronting (or vice-versa):
When Beta is fronting:
When Beta and Sans are both present and fronting:
When Delta's in a fight:
When Delta's in orange mode:
And that's all! Happy birthday to my fav <3