~ Gaster on at the beginning of Yet Darker

Gaster is a major character in Glitchtale who first appeared in Yet Darker. In the Glitchtale universe, he is Sans' and Papyrus' father, which was revealed in Camila's "easter egg" short. However, Camila mentioned that he won't be referred to as "father" or "dad" by Sans and Papyrus.


Gaster has a volatile personality, one caused by his time spent in the void. As seen in Yet Darker, his desperation drove him to disregard values such as family in order to restore himself. He had no issues with murdering, be it humans or monsters. He considers himself justified.

In Your Best Friend, His personality changed after exiting The Void completely, showing kindness towards Frisk and Sans. He's since adopted a composed and intellectual disposition since he is no longer trapped in the Void.

After Sans' death in Dust, he began speaking with concise language, and with a constantly blank expression on his face. He also became very vindictive towards Jessica for her contribution to Sans' death. He also resents her for the fact that she let Bete Noire take the HATE vial and never told them about it. Ironically, he shares similar behavioral patterns, as not telling Papyrus the truth about Sans' condition.

In Game Over, his sanity deteriorated further, unsurprisingly a result of sleep deprivation. He has shown extreme desperation, because of his desire to save Sans.

He doesn't seem to want to live too much as well, as he was willing to sacrifice himself for Jessica in Game Over, though after Jessica's last words to him asking for him to give hell to Betty, he seems to want to avenge her and destroy Betty at all costs.

In combat, Gaster relies on the distance he keeps between himself and his opponents, his fighting style focused around long-ranged weaponry. However, he has a bad habit of not using his powers to their fullest extent.

Powers based on Appearance

  • Can summon black spike attacks that are tangible and can be molded into different shapes
  • Can summon Gaster Blasters
  • Stops any form of resetting
  • Blocks the ability to teleport

  • Teleportation
  • Summoning of seven hands that can have human soul colors
  • The aforementioned black spike attacks
  • Summoning Gaster Blaster (possibly)

  • Teleportation
  • Summoning of seven hands that can have and change between the human soul colors
  • Can summon bone attacks (According to season 1 episode 4)
  • Can summon Gaster Blaster (According to season 1 episode 4)

Abilities and Powers

The following are listed to be only known for the series itself.

  • Polychromatism: Nothing is known about this special attack, and it's even unknown what this special attack can do. It is only known that this special attack is available when Papyrus and Sans are dead, we'll likely see this attack nevertheless because of the direction the series is currently taking.[4]
  • Chromas: Gaster has this special type of magic known to monsters as "Chromas". This type of magic allows the user to use a bit of magic with each trait known.
  • Teleportation: The ability to transport from one place to another in an instant. Since Do or Die Gaster is unable to regain his ability to teleport.[5]
  • Monotone: This is a special ability Hands to make the one(1) 7 times more powerful (as given by Camila Cuevas to Gaster. It changes the color of all shown on character card). It is seen in the 4th episode "Your Best Friend."
  • DUALITY: Merges his 7 hands into 2 giant ones. These 2 can switch between the original 7 colors and make combinations between them. The dual hands will follow Gaster’s hands motion and commands. The powers are according to each color just like in “Yet Darker”. And each attack these hands make as far more powerful than any of the 7 hands he originally had can attack.


Gaster and other monsters' memories

Screenshot 7

Only Sans remembers who Gaster actually was. He is Sans and Papyrus' father, but Papyrus only knows him as "Sans's friend". The other monsters are confused as to where Gaster came from but they don't question it either. To them he's just another monster that not many people knew about.

Small Gaster Official Comic

The comic shows a part of Gaster's past, and in the comic Sans and Papyrus do no exist yet. Gaster was on full power and Asgore appeared as a child in this comic. And it looks like Gaster's eyes change color depending on what ability he's using, which was shown when his eyes turned purple.

Easter Eggs

These are some easter eggs caught in some of Gaster's scenes in Wingding language.

Love Part 1 Easter Egg

Easter Egg Gaster 2

When the wingdings on the screen are translated, an system message appears about "The Experiment".


My Sunshine Easter Egg

Easter Egg Gaster

When the wingdings on the screen are translated, some information can be learned.

"The Barrier was created by 7 Human wizards, it explains why we only need the equivalent to/or 7 human souls to open it. I've been reading human history so I get more information about it's creation and see if i find something useful."

"All children seem to divide within the basic traits known...However only Frisk has a determination soul and it's % is higher than usual."

"The CORE will be the main source of power for the city it's expansion is already effective in some places. I'm figuring out why is the CORE related to resets. Tho is unclear. I think it might be my fault."


Yet Darker

This is Gaster's first appearance. In this episode, he plotted to take Frisk's soul so he could come back to life.


Gaster in Yet Darker.

After Frisk entered the Grey Room, he blocked their ability to reset. He proceeded to attack them with his black spikes. When Frisk attempted to leave, they noticed that the door was blocked by Gaster's spikes. Sans then fired at them with a Gaster Blaster. Instead of Frisk getting hit by the Gaster Blaster, Sans teleported in and blocked the attack. He then attempted to teleport themselves out, but nothing happened.

Gaster Episode

Gaster attacking Sans.

In order to escape, Sans blasts open the door and he and Frisk escaped from the grey room (killing a butterfly in the process). Gaster shortly left the grey room after them, partly materializing and becoming stronger as a result.

Yet Darker Gaster

Gaster capturing Frisk's soul.

Having returned to the real world, he summons his two of his hands. Sans knows that he cannot defeat Gaster, and attempts to take Frisk's soul like he did in the last timeline. Gaster interrupts, however, and he takes the soul instead, impaling Sans with a black spike. Frisk's Soul, about to be taken by Gaster, but it refuses to give in, and escapes from Gaster towards Sans's hand. Sans then takes the soul and fights Gaster. He eventually wins by destroying his hands one by one after his two hands get destroyed by gaster blasters and he summons 7 more. When the final hand is broken, a piece of his head gets cracked open. Gaster then says he just wants to come back, and will do so by any means necessary. He attempts to kill Sans with a black spike, but Sans is quicker and stabs Gaster in his back with a bone. Sans proceeds to reset the timeline afterwards using Frisk's Determination.

Your Best Friend


Gaster as he battles Chara.

After Chara's return, Sans used the device in his laboratory to resurrect Gaster, Sans then asked Gaster to bring them to the room where the six Souls were being kept and confront Chara, unsurprisingly enough, Gaster complies. Gaster used all seven of his hands to help protect Frisk while fighting Chara. However, he soon stopped protecting Frisk and instead decided to focus on damaging Chara. Chara tried to attack Gaster with one of their attacks, but Gaster put up a shield. Seeing this, Chara changed the direction of the attack and aimed for Frisk. As Frisk was unprotected, Sans teleported in to save them, but Gaster actually leapt into the blast, saving Sans and getting heavily injured.


Gaster didn't play a big role in this episode, he was only shown at the beginning talking with Undyne and we get a glance of him in the scene at the end where they look at the sun on the surface.

My Sunshine

Gaster is shown at the beginning where Frisk is proud of every friend that they knew. He explains how the core works, and how it'll help both humans and monsters due to the fact that there will be no need for electricity bills with it to Miss Grey. Gaster is later shown to start researching the pink soul of Bete as soon as he found out that she had a pink Soul.


Gaster was shown taking a nap, but then Frisk came to Gaster and woke him up. He accidentally dropped his coffee mug, almost breaking it in the process, however, it was saved by Gaster's telekinesis, who then went to refill it while talking about how Bete is going to move somewhere else. He said that he will read the story of two wizards that made the barrier later, then warned Frisk about the AMD cameras. He also told Frisk that Mettaton will do his first live report.


Gaster after Sans's death.

Later in the episode, Asriel and Sans go to check what is up with Betty. Gaster reads the story of the 2 wizards that made the barrier. He discovered that Bete is up to no good, and that her soul is the soul of FEAR, but it was too late to warn Sans and Asriel, as they had encountered Bete and found out the hard way.

Gaster was heartbroken when he realized Sans had sacrificed himself for Asriel. However, he gained 50% of his power back due to that.

Do or Die

Do or Die Gaster 3

Gaster prepares his Hands and Gaster Blaster

Do or Die Gaster 2

Gaster holds Akumu

Gaster played a huge role in this episode. In the beginning he talked with Frisk about how only one Determination and one Fear soul can exist at one time, and that only Determination can defeat Fear and vice-versa. He told Frisk that Fear is something that can be overcome. Frisk, after hearing this, became more determined than before, and Gaster overcame his fear of Sans's death.


Gaster attacking Jessica.

Some time passed after the attack of the pink blobs...

Undyne, Asgore, Papyrus and Jessica Grey came to their house/lab. Gaster sees Miss Grey and was about to attack her, but Papyrus blocked it and told him that she feels sorry about Sans's death thus making Gaster reluctantly forgive her.


Gaster using 👎🕆✌☹✋❄✡ (DUALITY)

Later in the Episode, Gaster, Miss Grey and Alphys go to the Core. Gaster went into the Nullifer room where he used his special attack Duality that made all of his 7 hands into 2 large hands which are much stronger than his normal ones. The Battle begins, both of them use all of their powers and fight each other. When the battle was almost coming to an end, Bete used Rhabdophobia and managed to take control of the 2 large hands and Gaster blaster. Betty severely injured Gaster with the Gaster Blaster. Then, he was saved by Dr. Alphys and Miss Grey, and was teleported out by Alphys alongside Jessica Grey.

Love Part 1


Gaster threatening Jessica.

After experiencing a flashback from when he fell into the Core, Gaster regains consciousness outside the Nullifier room. He attempts to teleport back into the Nullifier Room to aid Alphys, but is unable to due to the hole in his soul. After being told by Papyrus that Undyne was helping her, he notes that he is bleeding, and concludes that monsters gained physical matter over time after being around humans and eating their food; because of this, Undyne would be able to contain determination without melting as she fought Bete.

Despite being rescued by Jessica Grey, Gaster is very unfriendly to her because of her role in the deaths of his son Sans and of Alphys, explicitly mentioning that he would kill her if she wasn't one of Frisk's companions.

Love Part 2


Gaster looking at the night sky.

After Gaster was 90% healed up, he started getting some suspicious feelings about Jessica and went on her computer to check her stuff on the AMD program. He looked back to see if someone was watching behind him and then focused on the "Barrier Status" button. Clicking on it, he saw a recording that took place 37 days ago, seeing some kind of black blob moving around at a fast speed and then covering up the camera. Just after that he clicked to see the "Automatic Journal A.I" and he was really shocked seeing "Calling AMD director" in the Automatic Journal. For further information he went in Undyne's chamber, asking her about her battle yesterday with Betty. Gaster figured out she's the one with the highest chance to kill "this creature".


Gaster's anger.

He doesn't know how but she is able to create her own Determination which is Bete Noire's weakness. Shortly after Gaster questioned "Why couldn't you win?". Undyne said she got a power boost from the HATE vial. She was about the deal the fatal blow, but the substance made her regenerate all the damage she got and then retreated. Jessica hearing Undyne saying all those things made her look shocked and worried at the same time about what Gaster would do to her, Gaster crushed his pen in anger and almost used one of his attacks on Jessica, only for his soul to crack more a little. Gaster then calmed down a bit and started talking about the AMD being the only place to contain magical substances. He told Jessica this and was quite sad that she didn't tell them she had that vial. He started acting really sad when he said that she was the cause of Sans's death. He wished he'd never met Jessica Grey, making her lose her hair color and half her eyes' color and making her cry. After that, Gaster went in a room and sat there thinking about Sans's death. He got interrupted by Papyrus asking him if it's okay for him to come in. Without Gaster saying anything, he went in and sat back to back with him. Gaster, being confused, asked Papyrus "how can you be such a good monster, no matter what anyone tells or does to you, you forgive them as if nothing happened." Saying that, he got mad, asking him "DID YOU NOT CARE? Did you just forget about him? Don't you feel a thing?" Papyrus, being a bit sad about what Gaster said, answered that he misses him as well and there hasn't been a second of the day where he doesn't think about Sans. Papyrus said he can't let everyone else see him sad, because he knows they'll look up to him looking for someone to comfort them. And it has been difficult for him, everyone being sad and everyone getting hurt. Gaster, trying to talk, gets interrupted by Papyrus saying "That just means I have to try twice as hard to make everyone smile again!". Gaster says "Some things can't be fixed...". Papyrus answers that they can, showing Gaster that he fixed his mug, and tells Gaster he feels like Gaster is no position to deny someone's apologies when they made so many mistakes as well. Gaster, giving up trying to fight Papyrus, said Papyrus won and that he will try to forgive Jessica. Papyrus was glad to hear that, and asks Gaster if he got to see the stars last night. Gaster answered he did and that they were beautiful. Long after that, during Betty's battle with Frisk, Betty "asked for help", reviving Sans and controlling Sans using the HATE. Gaster and Papyrus are shocked that they feel Sans randomly come back to life, Gaster saying it's "Impossible." Gaster tries to teleport to where Sans was, but failed because he was still weak and couldn't teleport yet. Papyrus ran to where Sans was and Gaster started getting worried as he left the house, called for Toriel and Asgore to tell them where Frisk and Betty were fighting. Asgore was instantly convinced to go after them when he heard Toriel say she can't find Asriel and that she thinks he went after Frisk. Going after them, Gaster, Toriel and Asgore saw the fight happening and that Sans and Papyrus were there. Bete, getting mad that others were interfering in, used the HATE to create a shield that would get later destroyed by Sans when his soul got cleaned from HATE. Gaster started crying a bit seeing Sans back alive after he died. Toriel tried to heal Sans, telling Gaster that he had no injuries but instead he barely has magic to keep his SOUL together, making Gaster believe he is in some sort of coma. Papyrus tried to cheer them up by saying he believes in Sans and he will wake up.

My Promise

Gaster was first seen at the doorway after Asgore defeated a blob that Jessica was struggling with. He soon told Asgore that he, Papyrus, and Sans were going to go down to his lab, which was located in the Underground.

Some time later, Gaster was seen either at the entrance to his lab or at one of his lab's rooms. He was trying to remember the password to a door and questioned to himself how come he didn't recognize the area. He soon got hit with flashbacks of what happened at this place and his experiences in the void. Papyrus concerningly asked him if he was ok and Gaster responded by telling him that he was fine and that he just seen some flashbacks. He then remebered the password and put it in, opening the door.


Gaster then prepared a machine in the room to check Sans's condition. While Papyrus was off getting a requested notebook and pencil, Gaster made the machine reveal his condition. The second Gaster saw his unconscious son's status, his expression became transfixed. Papyrus soon returned and asked what Sans's condition was and if he would be ok. Gaster told him that Sans should be ok; he apparently didn't want to tell him Sans' real condition. He asked for Papyrus to watch over Sans because he had to go research something. Papyrus offered to help but Gaster persisted for him not to.

During a talk with Toriel, Asgore, and Undyne, Frisk apologized to for what happened to Asriel. But soon, Gaster joined the conversation, claiming that they were not hopeless when it came to Asriel's status. After refusing to answer Asgore's question on Sans' condition, he told them that, if Betty didn't destroy or drain the souls that she collected, then Asriel's soul and the other souls that belonged to monsters had a chance at coming back. He was asked by Toriel if the children that the children that blobs had killed could be revived. Unfortunately, according to his reply, the human children's souls were hopeless, due to their bodies being incapable of regenerating like how Sans body was recovered. He explained that Toriel and Asgore had to free Asriel from Betty's control. Therefore, he soon decided for Frisk, Toriel, and Asgore go to the arena. Once the group heard a bang coming from the outside, they decided to leave.

Gaster was later seen reading about Sans's real condition; fallen down. He was seen possibly trying to come up with a cure for his state. Once Asgore sat down while Toriel was attempting to heal him, Gaster looked concerned for him. Frisk later said that they wanted to talk with Gaster. They later went to his lab, there, he asked Frisk for something, their determination. Frisk said that they had found about Gaster's multiple experimentsm, and that they knew that one of them failed bacause it was supposed to be fueled with Determination, which is something Gaster didn't have back then. Frisk then said that they need Gaster to recreate what they tried to do, by using Frisk's soul as a power source. Gaster then said Frisk was attempting to fix their "condition", Gaster agreed but he warned Frisk that if they went to the Void they would have little to no hope of return, especially considering that Frisk is glitched. Though Frisk doesn't seem to let Gaster's warning stop them. Gaster then proceeds with Frisk's request, saying that it will be very interesting. Gaster then wishes Frisk good luck before they were transported to the Void.

Game Over Part 1

Gaster appears with Asgore when Toriel and Chara feels the effects of Frisk being erased from the timeline. Gaster explains how he also has had memory disarray. He then excuses himself to check on Sans.

Soon after, Gaster is seen dripping Determination into vials of “Monster Soul Essence”.

The vials explode, leading Gaster to almost entirely give up. Gaster remembers about Undyne’s Fight with Betty and goes to collect blood from the fight. He then proceeds to test it with Undyne’s hair, matching up 100% showing that the blood belonged to Undyne. He then appears back at the lab with a vial of ”Monster Soul Essence” with the previously mentioned blood sample from Undyne inside the vial. Gaster drips Determination successfully into the vial without it exploding.

Gaster then is with Sans, and injects Undyne’s blood with the Determination into Sans. However, Gaster’s plan of curing Sans from his “Fallen Down“ state does not work, since no one can "play god". Sans bones is shown to be cracking, accompanied with Gaster saying he failed. He only made it worse. Gaster then says that he made it that Sans will be awake to experience his death instead of passing in peace.


Later, after Jessica is called, Papyrus offers to accompany her. However, Gaster refuses to let Papyrus do so. Gaster summons his hands to trap Papyrus but Papyrus uses his Blue Bones to hold Gaster in place. Gaster manages to escape but not before injuring himself. He then proceeds to throw Papyrus into a wall. Papyrus says his pain of being thrown into a wall was not as bad as Gaster lying to him. However, Papyrus realizes Gaster’s pain and pities Gaster. Gaster says he doesn’t deserve his pity and claims that he has only made mistakes so far. After Papyrus helps him, Gaster offers to accompany Jessica instead of Papyrus, if Papyrus was ok with it.

Game Over Part 2

Gaster firing monotone at big boi

Gaster firing Monotone at the giant Pink Creature

Gaster first appears in this episode in transport with Jessica, on a train. Gaster wants to talk to Jessica about "many things", but cannot do so because he is tired. As such, Gaster takes a nap fro the rest of the ride.

Gaster does not appear again until later on into the episode, where he is seen standing with Jessica as she takes a call from Ronan. There Gaster is seen supposedly sensing a large cluster of magical energy moving. The cluster appears before Gaster and Jessica, while destroying building. Gaster and Jessica try to stop the cluster from reaching the school, along with other magical humans. Gaster and Jessica unfortunately get trapped under debris of a destroyed building. Under the debris, Jessica is able to move but Gaster is stuck under one of the boulders. Jessica has a teleporter but Gaster explains that the teleporter is only for one. Gaster tells Jessica to leave without him, and when she agrees, she shoves the teleporter into Gaster's hand, sacrificing herself for him.

Gaster is lastly seen crying alone about Jessica's sacrifice. He shows anger and a strong desire of vengeance.


  • Until My Promise, where he starting getting flashbacks, Gaster didn't remember what it was like being in the void.[6]
  • Since the beginning of Season 2, Gaster hadn't slept.[7]
  • According to a Tumblr post[8] Bete was looking for something in the Core.
  • Gaster knows and remembers every timeline.[9][10]
  • Gaster is a couple hundred years old.[11]
  • In a post, Camila has released a GIF of My Promise that features Gaster.
  • When Sans died in "Dust" episode, Gaster's blue eye disappeared and Gaster took back 50% of his powers. This makes Gaster stronger, not weaker. If Papyrus dies, Gaster will take 100% of his powers back and will have extraordinary power. At the same time, a special ability called "Polychromatism" will be available.
  • Gaster is a boss monster.[12]
  • Gaster cares about Asgore.[13]
  • Gaster is one of Camila's favorite characters, just like Sans.[14]
  • Gaster practically won the battle with Bete.[15]
  • Gaster knows that timeline will be erased if Frisk dies.[16]
  • Camila confirmed that Gaster hates Jessica to death.
  • Gaster's soul has a hole, and because of that, he can not use any magic and abilities until his soul fully recovers.[17]
  • While he was in "The Void", Gaster learned the ability to block the RESET and CONTINUE button.
  • Gaster's usage of black goop for attacking and blocking Frisk's ability to RESET in "Yet Darker" bears some resemblance to Chara's usage of HATE. The reason for that, and whether Gaster was using HATE, it unknown.
  • Gaster knew that only DETERMINATION could defeat FEAR, but the revenge blinded him from common sense making him not care about this fact and only wanting to exterminate Betty.
  • "Gaster" is actually Dr. W.D. Gaster's last name.
  • Gaster was a district leader on the surface before the monsters got sealed underground.
  • When Betty damaged his soul in Do or Die, it triggered Gaster's flashbacks of the void. And, ever since that, he has been questioning stuff he has never questioned before.[18]
  • His purple attacks copy every attack of the enemy that's in front of this hand. One of these was once used in "Yet Darker".
    • Strangely enough, he didn't use his purple attacks after Yet Darker, he didn't even use them during his battle with Betty.
  • Despite his claim that Betty was the first of her kind, this is not true, since the spell that created her had to have been used before to be able to deem it dangerous enough to forbid it.
  • Gaster lost his ability to teleport and to use his (already damaged) purple hand.
    • Gaster is unable to regain his ability to teleport. [19]
  • It was revealed by Camila that Gaster's cracks on his face were a result of the Human vs. Monster War.
  • Gaster was alive when Toriel and Asgore separated.[20]
  • Gaster's Parents and Ancestors were warriors for their kingdom.[21]
  • Gaster didn't have a good relationship with his family.[22]
  • Gaster's dad has the same power that Gaster does.[23]
  • Gaster's siblings did not possess Chroma Magic. But they were still incredibly strong and served as Royal Guards and Personal Guards for their kingdom.[24]
  • Gaster understood that his best friend, Asgore had to murder 6 children for the sake of his people, but he didn't agree to Jessica previously being Bete's accomplice.[25]
  • If Gaster lost his red eye, rather than his blue one, he would still have access to Duality.[26]
  • Gaster was trying to create/use artificial human souls when monsters were still trapped underground. [27]
  • Gaster was the only monster in his family to possess both Chroma Magic and Gaster Blasters.
  • Gaster was best friends with Shane Goldburn. [28]


  1. The names of Gaster's Parents (Link)
  2. The names of Gaster's Parents (Link 2)
  3. Gaster had siblings (Link)
  4. There's a special attack called "Polychromatism", nothing is known about this special attack and it's even unknown what this special attack can do. It is only known that this special attack is available when Papyrus and Sans are dead. (Link)
  5. Gaster is unable to regain his ability to teleport. (Link)
  6. Until My Promise, where he starting getting flashbacks, Gaster didn't remember what it was like being in the void. (Link)
  7. Since the beginning of Season 2, Gaster hadn't slept. (Link)
  8. According to a tumblr post, Bete was looking for something in the Core. (Link)
  9. Gaster knows and remembers every timeline. (Link 1)
  10. Gaster knows and remembers every timeline. (Link 2)
  11. Gaster is a couple hundred years old. (Link)
  12. Camila Gaster is a boss monster. (Link)
  13. Gaster cares about Asgore. (Link)
  14. Gaster is one of Camila's favorite characters, just like Sans. (Link)
  15. Gaster practically won the battle with Bete. (Link)
  16. Gaster knows that timeline will be ERASED if Frisk is dead. (Link)
  17. Gaster's soul has a hole, and because of that, he can not use any magic and abilities until his soul fully recovers. (Link)
  18. When Betty damaged his soul in Do or Die, it triggered Gaster's flashbacks of the void. And, ever since that, he has been questioning stuff he has never questioned before. (Link)
  19. Gaster is unable to regain his ability to teleport. (Link)
  20. Gaster was alive when Toriel and Asgore separated. (Link)
  21. Gaster's Parents and Ancestors were warriors for their kingdom (Link)
  22. Gaster didn't have a good relationship with his family. (Link)
  23. Gaster's dad has the same power that Gaster does. (Link)
  24. Gaster's siblings did not possess Chroma Magic. But they were still incredibly strong and served as Royal Guards and Personal Guards for their kingdom. (Link)
  25. Gaster understood that his best friend, Asgore had to murder 6 children for the sake of his people, but he didn't agree to Jessica previously being Bete's accomplice (Link)
  26. If Gaster lost his red eye, he would still have access to Duality (Link)
  27. Gaster was trying to create/use artificial human souls when monsters were still trapped underground (Link)
  28. Gaster was best friends with Shane Goldburn.