Sans (/ˈsænz/ SANZ) is the brother of Papyrus and a major character in Undertale. He first appears in the forest after the protagonist exits the Ruins. He serves as a supporting character in a Neutral and True Pacifist Route and as the final boss and heroic antagonist in a Genocide Route.
Role in the series
Sans appeared in some episodes of Sonja's Adventure Series or Sonja's Adventures of Kirby Right At Ya with Papyrus. He helps Sonja stop the Queen and her henchmen from attacking the Underground in Sonja in the Underground. He is voiced by Patrick Warburton (Who did Kronk from Emperor's New Groove.)
Sans is laid back, often sleeping on the job and taking breaks. His laziness is a combination of fatalism and apathy. He wonders if his indolence stems from his knowledge that any progress he makes will be erased when the timeline resets. Conversely, he suggests that this knowledge could be "a poor excuse for being lazy."
Though Sans is usually agreeable, he becomes eerily serious at particular moments. He is also observant; Sans reads the protagonist's expressions and can often tell when they have already done certain tasks. He enjoys making bad, skeleton-related puns, although the fact that he performs at MTT Resort hints that he may be a talented comedian. He enjoys science fiction and loves to drink ketchup. He also hates making promises. Sans may have a scientific background. Evidence includes the quantum physics book, workshop, his relationship to Alphys, affinity for science, and his timeline research.
Ellie Wilson Edit
Sans and Ellie had a brother and sister relationship, which he tells Ellie a bunch of jokes and he also loves Ellie's silly comments.
Sonja Farrington Edit
Sonja and Sans are great friends. Sans really tricked Sonja really well when he did the whoopee cushion in the hand trick, making Sonja feel better about missing Alister and the Lombax Five. Sometimes Sans jokes about Sonja and Alister's love when he sees Sonja and Alister being together all the time.
Sans cares for and admires his brother. He reads him bedtime stories and gives him presents under the identity of Santa. Nonetheless, Sans likes to mess with Papyrus, sending him bad puns on the UnderNet. He also leaves a dirty sock in their living room for Papyrus to fuss over.
Sans worries about others hurting Papyrus or taking advantage of him. In some Neutral Endings, Sans is afraid to tell Papyrus about other characters' deaths, so he lies about them going on a vacation.
Toriel and Sans share a love of bad jokes and are friends even though they never see each other face-to-face until the epilogue, the Family Ending, or the Exiled Queen Ending. Before the protagonist's arrival, Sans and Toriel shared jokes through the door to the Ruins.
In the Exiled Queen Ending, Sans becomes Toriel's roommate if Papyrus has been killed. In this route, Sans also states that he "can't bear to tell her what [the protagonist] did." If Papyrus is alive, the brothers visit Toriel often, play board games together, and sometimes convince Toriel to leave the Ruins.
While not being one to make promises, Sans complies with Toriel's request to watch over and protect any human that exits the Ruins. At the end of a Genocide Route, he indirectly apologizes to her, as he is forced to break his promise to stop the protagonist.
Though there is evidence that Sans and Alphys have a relationship, Sans only alludes to this in the epilogue.
It is also noteworthy that if Papyrus and Undyne are called just before entering the Laboratory, Sans will appear in the call and state that there may be dogs inside the lab. This hints that he knows about the true lab since Endogeny, an amalgamate containing several dogs can be found there.