Sans Undertale

Appearance: Sans appears as a relatively short and paunchy skeleton, with mitten-like hands. Sans is always seen with a wide, toothy-grin on his face. Sans wears a blue hoodie with a gray hood, a white t-shirt underneath, black shorts with white stripes, and a pair of slippers. He has white dots for pupils in his black eye sockets that disappear when he is serious or angered. When Sans uses telekinesis whilst fighting you, his left eye flashes light blue while his right pupil vanishes.

Personality: Sans is lazy, often sleeping on the job and taking breaks. His laziness is a combination of fatalism and apathy, as he is aware of timeline resets. Conversely, he suggests that this knowledge could be "a poor excuse for being lazy." He enjoys being mischievous. Sans primarily acts this way towards those he is on good terms with. His antics range from an assortment of illogical, juvenile, and slightly inconvenient pranks. Examples include Sans "selling fried snow," using whoopee cushions, sharing an unscrewed ketchup bottle, and eye paint on a telescope. He is not above utilizing his teleportation or other magic for practical jokes either. Sans is also fond of making the occasional low-brow puns. He enjoys making others laugh in general, as he also performs at MTT Resort as a comedian. Despite Sans being apathetic towards his own life, he is considerate to those he cares for. For example, Sans is a regular at Grillby's, and the monsters and Royal Guard dogs treat him kindly. Sans has informed Big Mouth about "all kinds of incredible foods," yet Big Mouth comments that "he always orders the worst burger off the menu." Although Sans hates making promises, he respects Toriel's request to watch out for any humans. Even if the protagonist killed people that were close to him, Sans refrains from broaching the topic until the Last Corridor. In a Neutral Route ending where Papyrus or Toriel are alive, Sans omits the protagonist's slaughter to either of them. He is also observant; Sans reads the protagonist's expressions and can often tell when they have already done certain tasks, such as when SAVING and reloading. Though Sans is usually agreeable, he can become eerily serious to emphasize a subject. Regardless of the human being partially or wholly merciful, Sans tells them that if "the old lady" (confirmed in the True Pacifist Route to be Toriel) had not made him promise to protect them, "(they'd) be dead where (they) stand." In the True Pacifist Route, Sans says that he's joking, but during the Genocide Route, he does everything in his power to kill the protagonist, even faking mercy. Sans may have a scientific background. Evidence includes the quantum physics book, his workshop, affinity for science, his inexplicable ability to teleport and his timeline research. Sans has implied he once longed and searched for a life that he cannot go back to as he "gave up trying to go back a long time ago". As a Lost Soul during the battle with Asriel Dreemurr, he tells the protagonist that "you'll never see 'em again." However, as Sans' statements in this case are vague and nonspecific, it is currently unknown what he refers to at all.

Backstory: After killing Papyrus, the protagonist continues to kill all the monsters in the Underground. Sans watches them secretly without confronting them directly, hoping they would heed his friendly advice and stop. Eventually, he decides to stop them himself no matter what. Sans confronts the protagonist in the Last Corridor but does not judge, instead claiming they must have been busy. He starts off by paraphrasing one of Papyrus' statements. Instead of answering, the protagonist takes a step forward. Next Sans laughs and asks "do you wanna have a bad time?", threatening them with force should they proceed. When the protagonist dismisses his warnings and continue to advance, he fights them. Before the battle begins, Sans apologizes to the late Toriel for breaking his promise to her.

Powers:

Bone lines: 16 lines of bones, which requires 8 small jumps to get through the gaps. The lines of bones appear from the left and right sides of the Bullet Board, and has a small gap between them. These are made out of small bones from the bottom, and longer bones from the top of the Bullet Board. The harder variant has the bone lines appearing quickly.

Blue bones: 6 set of bones appear from the left side of the Bullet Board, then another 6 appear from the right, for a total of 12 bones. The left side is a pattern of long light blue bone, then a short bone. The right is a pattern of a short bone, then long light blue bone.

Randomized bone lines: Randomized pairs of bone lines appear from the left and right. The bone lines can appear at varying speeds. These force the protagonist to jump at varying heights through the gaps. It can range from a total of 3 through 6 jumps required.

Platforms 1: Starting from the left is three green rectangle platforms atop a sea of bones. Near the top of the third platform is a set of three bones, and at the end of the sea of bones is a long bone from the top.

Platforms 2: Starting from the right is a longer platforming segment with seven green platforms. The fourth, fifth, and sixth platforms have a bone above each platform. The last platform has long bones appearing from the top left and bottom right sides.

Platforms 3: A segment with moving, long green platforms and bones that can block a path. The bottom platforms appear from the right, and the higher platforms appear from the left.

Platforms 4: The SOUL appears on a small green platform that moves left and right. The bottom of the Bullet Board is covered by a sea of bones, and three sets of levitating bones cover the near center. The center line of bones descends, while the outer two lines rises. The harder variant has more bones for the outer lines of rising bones.

Horizontal bone slides: Sets of small bones appear on the bottom, from the left, and large bones appear at the top, from the right. Platforms with Gaster Blasters: A segment with small moving green platforms and has thin Gaster Blasters. The bottom platforms appear from the right, and the top appear from the left. Thin Gaster Blasters appear to shoot above or below platforms from the left or right sides.

Gaster Blaster: A dragon skull that floats around and shoots beams of light blue energy from its mouth to kill people.