This is Sans from the animated series called UnderVerse. He went on an adventure with Ink sans too stop Cross (XSans). He met UnderFell Sans and UnderSwap Sans, Papyrus and Chara as well as OuterTale sans and Core Frisk. He was Spared by XGaster unlike Swap and Fell sans. He now is fully done with everything and is ready to accept that this is the end of his world due to XGaster. All of his friends and family are soon to be gone like himself… his friendship with Frisk isn’t that great anymore