Undertale OC Wiki
* Umm... H-hey, I couldn't see a thing!

* This article would benefit from the addition of an image.

* B-but it's okay!

* You can upload a picture to this article by going to the Upload page and selecting the file you wish to add to the wiki. Images that are of the .JPG format cannot be uploaded, and the file must have a proper name to be admitted.

Erebus (also known as Erebus Sans Gaster) is a Sans Out!Code created by Zeno Dreemurr, making his first appearance in Xénotale. Along with his brother Aether, he is one of Chaos's two children. He has the mission to gather information about the Multiverse to tell his father about anything that could be dangerous within it. As his name suggests, his powers mostly revolve on darkness.


After Chaos almost expanded itself on the entire universe of Chaostale, it wanted to expand on the Multiverse, as it ended up knowing about it. Since it knew that some beings in the Multiverse could be dangerous, it created two beings, Aether and Erebus, calling them its children, then inflicted them with a permanent variation of the Chaos seal. It then gave them the mission to get as much information on the Multiverse and its powerful beings. Both of them then started to investigate about it.



Erebus looks like an entirely naked version of Sans, entirely black, making him complicated to see in dark places. He also has a completely black sclera and black eyes, making those eyes impossible to see.


Being inflicted by a permanent Chaos seal, Erebus doesn't show many personality traits, and instead does a fixation on his father, being almost never kind to anyone besides his family. He is extremely serious overall and will fight someone that makes him waste time, not caring about adding to his list of murdered people whatsoever, and prefers to dedicate his time on researches. However, he does show some kind of intelligence by himself alone, making up strategies, and doesn't care about explaining how his abilities work as long as it doesn't give out information about a weakness. He also sees usefulness over many things, as he prefers to control people he deems useful, and would kill himself if he was to become useless. If Chaos dies, he is filled with a desire of vengeance towards the person who killed it by any mean, going from normal research to mass murdering, though he doesn't like killing at all.


  • Dark bone: The dark bones are bones that cannot be touched by light, and are therefore invisible.
  • Skoto-blaster: Erebus's Gaster Blaster. When those blasters fire, the beam seems to be normal, until it annihilates all light in the area surrounding the place the beam was fired at.
  • Great speed: Though he is not as fast as his brother, he can still move at a speed of just below Mach 1.
  • Invisibility: In exchange of being slower than his brother, he has another ability, which allows himself to be unable to touch light, turning him invisible. He often does it after a Skoto-blaster has been used.
  • Sixth sense: He has a sixth sense, allowing him to locate people even though they would be invisible, or if the place is filled with light or fully lacking of it.
  • Chaos seal: An ability given by his father. Using it, he can control someone he chooses to control for one day, unless this person has too much magical power for the Chaos seal to bear it. Thanks to the Chaos seal, not only he can control his victim, but also communicate with them via telepathy and know everything about them. He can also use all of the abilities of every person he has control over thanks to a Chaos seal. If someone else uses a Chaos seal on someone he used the Chaos seal on, the new Chaos seal takes priority over his.
  • Dual chaos seal: A variation of the Chaos seal he uses with his brother Aether. This variation allows for both of the brothers to have the advantages of the Chaos seal, and lasts three days instead of one.
  • Regeneration: As long as his entire body isn't annihilated, he can regenerate it out of nothing. It takes three seconds to be activated after being harmed, the regeneration being completed in a matter of seconds at worst if his opponent stops attacking him.
  • Chaos soul fragment: He and Aether share the chaos soul, a soul made out of no matter, both having a fragment. It allows him to be immune to any kind of soul alteration. It also allows him to communicate with his brother via telepathy, and also makes him capable of regenerating his body as long as his brother is still alive.



Aether is his brother. His brother is the only person he shows some kindness to, being made to be a team. Unless they are forced to not, they are always together. More often that not, they fight well together, and choose to use a dual Chaos seal over a normal Chaos seal.


Chaos is his father. Because of the Chaos seal, he pledged loyalty to it, doing a mission for him. When he sees it, it is often to give it information.