Sans is the same to Sans, the Supporting Character in Undertale.
Sans wear a fluffy hoodie, with two yellow stripes and yellow sleeves. He wears a blue jacket with two yellow stripes, and he wears fluffy slippers with stars.
Sans also has a supporting, caring personality. In Outertale, Sans cares about Frisk much when Frisk supports mercy.
When Frisk supports Fighting, Sans's personality changes. He becomes concealed, and much like Undertale Sans, judges the player very harshly.
Sans also likes puns, very much. So much that it annoys his younger brother, Papyrus.
Outertale Sans is also sometimes depicted as a bit shy.
While Sans makes more puns that will annoy his brother, He cares deeply about him, since they have a brotherly relationship. When Papyrus dies, Sans starts to stalk Frisk in grief, watching them and seeing what do they do.
Sans has some connection with WD Gaster he is the only one who remembers him and his brother Papyrus no, he was the real Asgore scientist .... Sans played WD Gaster in his own creation to protect his brother and that's how they grew up on Stardin.