Underswap Chara

Scenario: The first floor of this house contains a living room and a kitchen. The living room features a television that is always set to one of Mettaton's shows when turned on. The living room also hosts Papyrus's pet rock, which is covered in sprinkles, and one of Papyrus's dirty socks with a series of sticky notes attached to it. These sticky notes depict Sans nagging Papyrus to pick it up. The living room also contains an old couch that gives the protagonist 20 GOLD when they first check it, and a joke book that contains a quantum physics book which contains another joke book containing another quantum physics book. The protagonist decides to stop at this point.

The kitchen contains a stove with an empty pie tin in it, a trash can, a tall sink, and a fridge that has containers labeled "tacos" on one side and an empty bag of chips on the other. The second floor of the house contains a framed painting of a cartoon bone and doors leading to Sans's room and Papyrus's room. The door to Sans's room is plastered with labels reading (NO GIRLS ALLOWED!), (NO BOYS ALLOWED!) and (SANS ALLOWED.) The door to Papyrus's room has multicolored flames under the door which do not hurt the protagonist if stepped on.

Sans's Room is where the protagonist befriends Sans. His room contains a racecar bed, action figures, pirate flag, a bookshelf with complex tomes about puzzle creation and children's books, a computer opened up to a social media website, a box of bones, and a closet with clothes neatly hung up inside. Papyrus's Room is unlocked in a no EXP earned Neutral Route by listening to Papyrus in the Last Corridor explain EXP and LOVE and then reloading the SAVE file. This can also be accomplished by having already completed the Neutral Route once and then returning to the area in a second Neutral Route. After either method, Papyrus notices the protagonist has already heard his spiel and exchanges one codeword, and then another, which is revealed by reloading again. Papyrus then gives the protagonist the key to his room, which mysteriously appears on the protagonist's keychain.

When the protagonist first enters the room, they walk into what is seemingly an empty void. After a bit of walking, Sans turns on the lights to the room and tells the protagonist that they were using a treadmill in the dark. Papyrus's room is messy, containing a self-sustaining tornado of trash, an unused treadmill with a note that reads "the truth is that you got owned, nerd....." It also contains a dirty sock pile, a worn mattress with sheets bundled up in a weird creasy ball, an uncovered pillow, a "thank you" letter addressed to Santa, a lamp with a flashlight that is out of batteries stuck in the bulb socket, and a drawer with a Silver Key, clothes, and trombones inside of it.