the name's sans, sans the skeleton. i'm new in town.
Sans to Kris
Sans runs a self-titled grocery store in Hometown as the "janitor" (despite there being no-one else working there).
Sans's dialogues are written in lowercase and use the Comic Sans font, hence his name.
Sans appears as a short, paunchy skeleton with a wide smile and large eye sockets. He wears a blue unzipped hoodie, white shoes and black shorts. Sans also possesses white glowing pupils in his eyes, depending on the sprite.
Sans appears to be a laid-back character who enjoys messing around with others for his amusement. He also seems to be amiable towards Kris and eager to interact with the citizens of Hometown. It is notable that he deeply cares for the well-being of his younger brother. Sans enjoys making jokes and puns, as shown when he interacted with Toriel in his store after she forgot the eggs she brought. Despite his carefree personality, Sans gives good advice to those who need it. When Asgore asked him what flower would remind him of the time he and Toriel first met, Sans responds that he should probably "talk to his plants."
Sans never expresses surprise or confusion. When Kris greets him as an old friend or asks for news about his brother despite never having heard of him before, his only reaction is to wink at Kris.
After returning from the Dark World, Kris can visit Sans, who makes a brief appearance in this chapter. It is revealed that Sans owns a "grocery store" (a closed-down Grillby's from Undertale) and that he just recently moved to the little town. He requests Kris to come over to his home to meet his little brother. He also claims to have recently "befriended" Toriel.
If Kris chooses the option "Friends" and then "Me" when talking to him, he gives them "his phone number." However, when called, it directs to a hotline for idiot babies. The option then changes to "Not Sans's Number" and rings indefinitely if called. If Kris once again offers to be Sans's friend after having called the hotline, he says that he refuses to associate with "idiot babies."
When Kris starts to leave, Sans says that he needs help with something. Kris can choose to answer with yes or no, and Sans has different dialogue depending on how much time Kris took to answer.
After returning from the Cyber World, Kris can enter Sans's grocery store and speak with him. Walking to the left side of the store triggers a cutscene where Toriel buys eggs, and she and Sans exchange egg jokes before being interrupted by Asgore. Kris may choose to talk to Sans about his brother, and he says that things didn't work out and Kris cannot meet his brother today. However, if Kris did not speak to Sans in Chapter 1, he expresses surprise that Kris knows about his brother and jokingly denies having one. He also has some interactions with Susie, who finds his sense of humor exasperating.
- Sans's unseen or spoken to younger brother is implied to be Papyrus, his brother in Undertale. When inspecting the door to Sans's house in Chapter 1, Kris can hear a "distant trousle of bones," referencing Papyrus's fight theme in Undertale, "Bonetrousle." When inspecting the door to Sans's house in Chapter 2, Kris can hear "a trousle... growing further away..."
- Sans is one of the only returning characters from Undertale in Deltarune who does not have a new design, along with Froggit.
- Sans has an unused sprite showing his dialogue portrait without pupils. In Undertale, this face is used when Sans becomes serious.