Who Dr. Gaster Is and Why That Matters to Deltarune 

I can't believe we're at the point when we are like "we gotta explain gaster to the kids"

"Gaster has to babysit his boss's kid for all eternity." Even without the context of who Chara is, that is a version of Hell on its own.

"Does Gaster mug you?" "Two of them." "Maybe Gaster has to babysit his boss's kid for all eternity." God I want this characterization to be Canon.

Something I noticed is that during the height of undertale’s popularity Gaster was portrayed by fans as a tall calm/collected person but when the first two chapters of deltarune were released fans started portraying him as a silent large uneven monstrous shadow accompanied by quiet whispers and broken speech. This is probably because Gaster has an actual presence in deltarune looming over everything which is most likely what caused this change into something more monstrous.

The funniest thing to me is how, if the mysterious narrator really is him, it means that canonically Gaster is an avid user of Twitter.

THEORY: Gaster’s theme is intentionally simple, we’re hearing it everywhere because his pieces were scattered everywhere when he shattered through time and space

13:46 There’s no VERY, VERY INTERESTING, but if you name yourself “KRIS”, “SUSIE” or “NOELLE” you’ll get the voice telling you you’re about to meet someone VERY, VERY WONDERFUL, so

the end of the "garbage noise" even sounds a bit like a scream, and to me that makes sense because, based on what happened to gaster and his current form, he must exist in some form of pain

Let's be honest here, if Toby were ever to confirm that the mysteryman sprite isn't gaster, the Fandom would go absolutely ballistic. 1000's of fan fiction writers' dreams would be crushed violently.

Gaster is canonically aware of Covid This is the most mind blowing thing in this video

I absolutely love how there's ONE piece of text we get from Gaster. We hear (or uh.. see?) him speak ONCE But we almost immideately knew it was him in these tweets and at the beginning of the game just by the speaking mannerisms and the wording he uses. IT WASN'T EVEN THE SAME FONT!!!!!! And here ladies and gentelmen is what good fucking writing is.

I was there in 2015-16, i saw all this gaster lore unfold after my very eyes, yet i still sat and watched a 20 minute video of mostly stuff that i already knew because of the sheer enjoyment i get from seeing people taking coverage on topics like these. Great video, i genuinely wonder why i didn't comment when i first saw this last year

I love how Toby essentially implemented a hidden creepypasta character into his games lol

When you name yourself "Susie" in Deltarune, the narrator says "you are about to meet someone very, very wonderful". He also calls some names "an interesting coincidence". So the connections are there.

"It wouldn't be very Big Shot of Gaster to make the seizure warning indescifrable" - Misty

One weird thing I want to point out. "Man" is usually used to refer to the egg person, while "Him" is usually referred to Gaster, and the sprite is spr_mysteryman. It is still, very possible that this is referring to Gaster as the 6s and the mus_smile file suggests. But, I just find it weird and wanted to point it out. Note: Thank you for the comments for pointing it out, but gaster is referred as a man at the river person dialogue. There is no confirmation that he's actually is talking about gaster though, since the dialogue is vague enough just enough to let toby put the most fucking mild-blowing 4d arg play into that line

I love the idea that eventually once Toby actually shows Gaster, it’ll just be a completely different design than what the fandom has given him

"It wouldn't be very [BIG SHOT] of Gaster to make the seizure warning indecipherable" LMFAO

i’d also like to note that the rabbit shopkeeper in snowdin says that sans and papyrus “just showed up one day and asserted themselves” and that nobody knows where they came from if gaster WAS their father (or at least guardian) it would make sense if he was written out of existence, and by extension, sans and papyrus’ connection to the town, since they probably would’ve been living in his house. also, since it can be assumed that sans worked in the lab at some point, it’s possible he was working WITH gaster, perhaps even when he fell. and, y’know, seeing his own dad/relative/guardian be “scattered across time and space” might make you a bit aware of timelines and the quality of reality. might explain how he’s so aware of the player’s meta actions. Also! Another thing i find interesting; we’re told that gaster “fell into his own creation” after we’re told he built the core. I fully believe this to be a red herring. “Falling” or “being in a fallen state” is analogous to death or being close to dying in undertale. If we go with the assumption that Gaster helped, or even started, the determination experiments we see Alphys working on, we could assume that he experimented on himself, melted from the determination exposure, like the amalgamates, and “fell.” this could also explain how he “shattered across time and space,” as those with high levels of determination are able to mess with reality and timelines and stuff. anywhizzle, this is such a great video!! i keep coming back to it to sate my gaster hyperfixation, my adhd thanks you

Theres one other Gaster allusion in the hometown that wasnt mentioned. Iirc, when you approach the mysterious doors at the bottom of the Town, it plays a specific sound while near them. If you take that sound in the files and speed it up by 666% in an audio program, it's actually just the Garbage Noise that plays in entry 17 and on Kris' phone. Whatever happened to Kris (and maybe Noelle if we consider her words from Snowgrave) at that door, it could have connections to Gaster. My current assumption is that Gaster has formed some kind of connection with Kris, like he did with Jevil and Spamton, which is why there have been multiple comments on how Kris has changed recently and why they hear the same noise on their phone that Spamton did.

One more reason people think Gaster is the skelebros' father, is because no one remembers him and skelebros are said to have just shown up one day. If their creator/parent was erased from everyone's memory, it would make sense for people to see them as if they just appeared out of thin air. Of course this is just a theory, but that is the strongest piece of evidence for it IMO.

Small brain: Gaster in Deltarune is an Undertale reference Big brain: Gaster in Undertale is a retroactive Deltarune reference

I'm finding this video over a year late, but it's so weird to me how, even if I played Undertale back then, intentionally staying away from the fans made the whole experience with the game very different, I rememeber seeing some videos of some "cool easter eggs" in the game and that's all I knew about Gaster and honestly didn't care at all about him, meanwhile the fans were apparently going insane over this weird ghost skeleton man

I think that Gaster is Grandpa Semi, because “semi” also calls to mind “semicolon,” and you could look at the mystery man sprite’s eyes as being a slightly embellished semicolon. It also ties into the font lore of skeletons and Gaster, as they focus on the format of the written word when they speak.

My brother’s favorite Undertale memory is when he played the game for his first time and came across the gray door in Waterfall out of sheer coincidence, but he decided to skip the door and come back to it in a second not realizing that the door and hallway would disappear after leaving. He then told me about it (around this time I was deep into canon lore and fan theories and knew all about Gaster), and I just stared at him for a second and told him that he found a rare chance happening and just left it. He laughed so hard. Honestly pretty hilarious now that I’m typing this out lol

Speaking of gaster, my biggest regret was not entering the mystery man room when it appeared on my first playthrough because I was playing blind.

I thought I knew everything about Gaster. This video made me realise how similar he is to the humans who fell into the Underworld: falling into ever-expanding darkness you have no way out of. Blew my mind!

Don’t forget about that bunker in Deltarune where if you higher the pitch of the noise that plays near it it plays the garbage noise Also jevil and spamton give you shadow crystals that are described as pieces of glass and in Undertale they say he shattered across time and space so glass shatters and they could be literal pieces of gaster

“Gaster has to babysit his boss’ kid for all eternity” I love that

It’s very fitting that the character who was scattered across reality has a theme simple enough that it can be heard in the background of most songs

I will forever subscribe to the Handplates interpretation, purely because it is so incredibly well written and at no point goes hard enough against canon that it could be ruled out. Zarla has my support in their cannon.

Could "Gaster" be a pormantaeu of "ghast" meaning ghost, and "aster" the font? It would kinda make sense considering Gaster's etherial presence in the world.

fun fact: I was like 12 when I played Undertale for the first time, and I was absolutely SO UPSET by having to leave Toriel. I was calling her, over and over again, in every room, only to get no response... and then I got the wrong number call and I swear to god it made me cry

Can you imagine if Undertale came out before datamining and the internet was such a big thing? One day, you're playing through it like usual when you see a weird, grey NPC who mentions a guy called Gaster who never comes up in the main story. You never see this NPC again on any subsequent playthroughs. You post on a forum to ask if anyone has seen anything like this and the only responses you get are "idk man sounds like a glitch or something." or people assuming you made it up, and you're left to wonder if it did actually happen

13:15 gaster wants to show you his pokemkn card collection.

My nephew had no idea who Gaster was since he was never a part of the fandom since he's 8- but he watched the entire video without speaking and was very interested in it and I've never seen him be this interested in a video lol

I genuinely never thought of how new fans would see Gaster until now He was such a big deal back in the day with comics and theories sprouting practically every week so it's insane that some people don't know him

I absolutely love the idea of gaster having to babysit chara for all eternity

i like this channel a lot. they constantly sound like they’re on the verge of laughing at all their silly jokes and im here for it

I know who Gaster is but I love this video so much. Feels like old school theorising where we're grasping at the very little we have and it's got such a mysterious vibe, I don't need answers I just need clear and concise clues (fnaf I'm looking at you). Anyway thanks for this video even though it's kinda old, it's sort of a comfort video to me learning about our possible skeleton possible threat possibly doesn't even show up guy.

"now gaster has to babysit his boss' kid for all eternity" my god, that's by far the funniest thing i've heard this week 😭

Here's my own take on why Gasters theme appears everywhere: Gaster was shattered across time and space. His musical representation then ALSO is shattered across time and space. Giving you a feeling of him always being around, watching.

I’ve always been a fan of undertale, but never was interested in the fandom as a whole and looked down on it a bit (mostly because I was too old for it and they were a bit rabid back in the day) so when you mentioned fandom, I was more then a little worried this video would be difficult to watch for people not into the culture. However, I was pleasantly surprised that the video is very friendly to people out of the loop and enjoyable to watch. Good job on the intro parody by the way, hearing that specific theme (was it called “fallen down”?) was a nostalgia trip.

a favorite theory of mine that I can't remember if I came up with or not: when gaster was scattered throughout time and space, you can see him everywhere, in every town and around every person... Dr. Wing Ding Aster was splintered into countless asterisks. * He's right there. * At the beginning of almost every line of dialog every character speaks. * He's always been there. * He always will be. * Silently watching, reading your words, your thoughts.

I can imagine Toby sitting at home looking at people's fanart and comics depicting Gaster as mystery man just laughing saying "hah! That's not even him lmao"

i love how not only does "gaster" as an enemy cause you to lose money, basically mugging you when defeated, he also causes you to lose xp, meaning he somehow drains your experience when defeated.

“Ridiculously talented Musician And Leit Motif Enthusiast Toby Fox” is one of the best description of him and his work I’ve ever heard. 23:55

I really like this video. You sound like you’re having a blast and grinning the whole time. Plus, having such a concise explanation over a massive trail of breadcrumbs spanning years and two games is very nice. Cheers!

18:06 "I will say that gaster seems to have a real talent for suddenly disappearing from existence" I know this isn't meant to be taken at face value, but I can't stop giggling over the idea that Gaster was actually just helping Spamton but then suddenly disappeared from existence mid conversation.

Imagine if it was completely intentional to have gaster’s theme everywhere to make it feel like he was truly everywhere

Thank you so much for this video, I didn't even know where to start to research Gaster and I couldn't make heads or tails of what I did find. You summed everything up perfectly and it's made my Undertale & Deltarune experience a lot more interesting 💕👀

Gaster kinda reminds me of a more mysterious and creepy version of Professor Paradox from Ben 10 Alien force, while Professor Paradox was a good guy who traveled from multiverse to multiverse helping to make sure the timelines and everything is fine, one of my favorite characters- then you have Gaster, this ominous figure who is basically unknown, in my little head cannon- who has a morbid curiosity when it comes to multiverses and timelines and stuff like that

I actually find it pretty creepy how Gasters theme is in so many seemingly unrelated pieces of music, like he's been entwined with the fabric of reality and is revealing himself through subtle changes in it.

Something I feel like a lot of people aren’t talking about enough is the fact that, in the Deltarune timeline, Gaster should still be alive. No royalty = no royal scientist = no experiments = no “creation” = no falling into “creation” = no space time bullshit blah blah blah you get the idea. Unless the space-time-shattering affected him across all timelines somehow, or something else happened in this timeline to achieve the same result. Maybe Gaster as a character is just “doomed” to a fate such as that, similar to how Deltarune Burgerpants seems to be “doomed” to live a similar life to his Undertale one despite the radically different circumstances?

This is one of the best written video theories/essays i've seen in a really long time, and the humor makes it even better. Keep up the good work

9:18 Beware of the man who came from the other world.

I actually also think Gaster is more likely to be a Deltarune character since many things we know about him could be forshadowings to deltarune. Also Toby wanted to make Deltarune bwfore he came up with Undertale.

“It wouldn’t be very big shot of Gaster to make the epilepsy warning indecipherable”

Deltarune is turning out to be such a beautiful game as the chapters release when they can be released. Updates are given at times and it's not rushed. When the next chapter does come out and hype has basically died, the gameplay, music, everything really, brings the community swinging back to the game and everything just jamming out.

Very excellent video! As a day 1 (or close to it) fan of the series, I had never considered that newer members had no idea about the ominous and horrifying shadow monster man that is constantly watching our every moves throughout the game.

"Gaster has to babysit his boss' kid for all eternity" I love the idea that Gaster gets excited about what he and the player makes, and Chara just comes in and destroys it like a toddler drawing on their parent's papers

i NEED a story where gaster and chara go around AU's in a ''grumpy uncle and adopted child'' story

this video is a year old but i gotta say i love the joy with which you speak in this video, especially when trying to voice gaster. thank you for speaking the truths to me kind individual

This is my comfort video thank you for making it

I like to believe that his “creation” was actually Deltarune itself. A world where monsters and humans could live together in peace. He fell into his creation, and pieces off himself were shatters across time and space. A bit in Undertale. A bit in deltarune. Maybe bits somewhere else.

"It wouldn't be very BIG SHOT of Gaster to make the epilepsy warning indecipherable" is such a great string of words to me for some reason, especially if someone had never heard of Undertale before

I got here from a nasty food comp with the sb foghorn sfx

imagine if toby is laughing at how everyone thinks gaster is some tumblr sexyman skeleton in a black and white suit (based off of the mysteryman sprite) when really he looks completely different in canon (Obviously the mysteryman sprite has a strong connection to him, but that doesn't necessarily mean that it IS him)

7:07 to be fair assuming that this call is Gaster related by the G alone might have been a stretch a few years ago, but now with the retrospective that Gaster is often associated with phone calls I don't think it's too outlandish of an idea.

considering Gaster was "split apart time and space" it makes a weird amount of sense that his very simple 4 note theme could be vaguely heard in every other theme

I LOVE the "you had to be there" factor for Deltarune ch1's initial release. The tweets. The survey program file. Not knowing what it was then being MINDBLOWN when it turned out to be an entire new game. It was fantastic. (Honestly given that Toby was working on deltarune so far ahead of undertale, im like 99% sure the reason that gaster was so vague in undertale was that he was a teaser for deltarune)

As a very avid writer who enjoys foreshadowing in the most obscure of ways, I am 100% convinced Gaster was always planned to be a big part of Deltarune, and any blatantly obvious Gaster insert into Undertale (like the fun value 66 door) was just Toby deciding to play the super long con and foreshadow 10 odd years in advance.

Let's not forget Gaster's (possible) association with eggs, with the mysterious "man behind the tree" Now let's combine that with the royal scientist's great fall, and being shattered across time and space, never to become whole again. And now we arrive at the conclusion that Gaster is in fact... Humpty Dumpty That's right I think Gaster is Humpty Dumpty and you can't convince me otherwise.

I'm surprised you didn't mention the man behind the tree that gives you eggs (egg in wingdings is left forward forward, the move that knights perform in chess)

I love the line "Don't forget, I'm with you in the dark." In the UT/DR Pacifist route, that's comfort from the player's friends that they are being told. It could be Sans, Susie, Asgore, Ralsei, etc. In the Genocide/Weird route, though, it's a threat. From the player to Frisk/Kris.

I feel something that’s been kinda lost in the fandom hyperfixation, is the fact that Gaster is legit scary For one, Mystery Man’s sprite is very spooky, and Gasters theme is also very ominous And like, imagine finding all of this stuff for the first time Toby did really well making Gaster and his entire story, and I just want to respect that

i actually love gasters theme being everywhere directly relates to him being "spread across time and space" he's LITERALLY been spread everywhere to the point of weaseling his way into all the music

You forgot the door at the bottom of Kris' HomeTown in Deltarune. It's a misterious door that "won't open". When you get close to the door, you can hear very, very, very, but I mean, VERY slowed down version of the garbage noise. Very, very interesting isn't it?

Also, the Z's that appear when Sans falls asleep in his battle in the genocide run are in the Aster font. It doesn't appear anywhere else in the game but there. That's why I find it so ridiculous that people make grand theories of what will happen but leave Sans out entirely. He's clearly connected.

Since we have no concrete evidence of what Gaster looks like and him being shattered across space and time, I believe both the mystery sprites in the hidden rooms are parts of Gaster. The mystery man sprite is his main body, and the wispy white sprite is his flowing luxurious hair after a few years in the void with no shampoo.

Snowdin Town's theme in Undertale also has the "Don't Forget" leitmotif in it. Which is fitting since that's where Sans' lab with the Don't Forget photo is located. Bonetrousle was originally meant to be Deltarune's battle theme before it was repurposed for Undertale, so it makes sense that Toby would've written a lot of these themes and melodies before Undertale came out. Also the Bunker in town plays the entry 17 noise when sped up by 666% Edit: Also also, Queen says that Noelle needs to "close her eyes and sleep away into a darker darker dream" in the snowgrave route, and Gaster's theme is 100% present in the song playing during the hospital scene where Noelle is talking to herself. Edit2: In the ch 3-5 teaser songs, Toby put the Snowdin Townin motif in Deltarune's new hometown theme

Gaster fascinates me because it seems as though he's everywhere and nowhere. Like a quark, or a gluon, he exists and he's all around us, yet he's almost impossible to see or measure. He passes right through the world, almost never interacting with it in any way that we can see. It makes me wonder whether Toby might have been reading about particle physics when he came up with Gaster and the broader idea of Deltarune.

One point for Gaster's Theme, it appears very prominently at the end of a "kill everyone" run in Chapter 2 when visiting Noelle and Rudy at the hospital. It's not hidden at all, very very interesting.

The 6 recurring isn’t just because its an “evil number” I think it is because it is the number that most closely represents his letter G, G and 6 are meant to be associated with him

"Does Gaster mug you?" The research grants aren't cutting it anymore now that he no longer exists.

something i literally didn't think of until a few days back, mettaton's quiz show "fight" has the question of who alphys has a crush on, and if the player chooses nothing, mettaton mentions that alphys seems to believe that there's someone outside their reality that is watching her. while mettaton completely combats it and mocks alphys in-game, and while the argument could be made that the vagueness is in reference to the player themselves, it could also be that alphys knows and/or believes gaster to still be out there and his presence to still be alive, and that she has/had feelings for him. it makes sense given that they're connected through their job, and that it's implied that sans, alphys, and gaster were working on things together. plus, alphys is confirmed to have a crush on asgore, so we know she is attracted to men, and that it's possible she had come into contact and known asgore prior to working under him as the royal scientist. just a thing i've noticed recently that i wanted to mention! gaster's presence is so intriguing and i can't wait to see what the future has in store for deltarune, both with possible ties to gaster as a character, and just as its own series!

Finally someone explains it. It always felt like an inside joke or secret when people talked about him.

I'm incredibly surprised this barely mentioned the "What do you two think?" line. This was what really confirmed in a ton of people's heads that Gaster, Papyrus and Sans were related in some way since they made the most sense in a lot of ways to be who he was talking to. Even if you don't think the "you two" he's asking were Sans and Papyrus then it becomes a huge mystery to figure out, because obviously it means Gaster had some sort of close relationship to 2 characters we most likely know about

"Too vague to prove anything, but notable enough to not dismiss it entirely." ^ Literally ALL of the undertale lore

No one seems to have mentioned this so... There are a few strings of failsafe text that happen in Deltarune if the game somehow loads a conversation without assigned dialogue. One of these is very very interesting to say the least. Is that a cut on your face, or part of your eye? The gash weaves down as if you cry. The pain itself is reason why. This seems to be referencing the mystery man sprite from Undertale. While this alone could be dismissed as a coincidence, the second failsafe text string leads me to believe that this may be confirmation for mysteryman being indeed, Gaster. You can't read these symbols... Or maybe it's the handwriting. Now this one seems way more suspicious, because it seemingly references the WingDings font that Gaster is associated with. Again, no direct confirmation, but it's still something worth considering.

He "fell into his creation." I love this line. Let me ramble a bit. The song during the character creator in Deltarune Chapter 1 -- or rather, SURVEY PROGRAM -- is "Another Him," and you're making what's explicitly called a "creation." Our creation. And after it's discarded, the narrator explicitly tells you that you cannot choose what you are, and tells you your name. But we never hear the end of that sentence. We never hear our name. It fades to white, and Toriel immediately cuts in, waking Kris for school. The end of the narrator's sentence is left open, but the implication is there. But Kris... isn't just one person. The endings of both chapters make it rather clear there's a duality. A creation. A survey. One person. Two beings. "What do you two think?" I bet all the money in my pockets that if we hear that question again, the only recipient will be Kris.

Frankly, the best way of explaining all the Gaster stuff I've seen. Not trying to lean into the creepy aspects in an over the top way, just presenting the facts and theories in an informative and fun manner. Thanks for the great work!

The first time one of my friends played Undertale they got Dr. Gaster‘s room to appear and thought to themselves “oh that’s an odd place to have a door I’ll just come back to this later” then they came back later and the door was gone lol

Fun fact: The singer who sang "Don't forget" also sang "There's zombies on your lawn" for PvZ.

Another thing that connects the mistery man sprite to Gaster: When you interact with him a sound effect is played and he disappears, if you take that sound effect, change the speed by 666% (don't remember if it's sped up or slowed down) and loop it, it sounds like Gaster's theme

actually thats brilliant "photon readings are negative" not as in there are no photons but literally negative light creepy how wordplay can be

I'm surprised you didn't mention how the noise played at the shed in Deltarune is the same as the noise during entry 17 when sped up by 666%

A couple of other connections you didn't mention: -Sans and Papyrus are specifically mentioned to have randomly appeared in the underground, which makes no sense given our understanding of how monsters ended up there in the first place. This could mean they were either created (presumably by Gaster, either intentionally or as a result of him being shattered across time and space) or that they came from another universe, like Deltarune (but maybe not Deltarune specifically). Sans even mentions giving up on "going back" as if the world he is in is not his home. -Sans' dialogue during his fight in the genocide route, his secret lab behind the house, his quantum physics book and his connection to Alphys imply that he was some kind of scientist at some point (he even hints that he knows about the amalgamates before you go into the true lab). Gaster was ALSO a royal scientist, so they may have worked together and whatever accident destroyed Gaster may explain Sans' strange abilities like teleporting and having knowledge of resets, LV, etc.

When they mention the Gaster's motif in Undertale songs, they should have said "in the description will be a playlist with all the songs for the possible Gaster's motif" and then when you go into the description it's just the entire Undertale soundtrack

Something that's honestly kind of terrifying about the core is that, if you fall in and die, not only will you not technically die, but everyone will forget you ever existed as well