Papyrus

Papyrus (/pəˈpaɪɹəs/ pa-PIE-rus), known as CoolSkeleton95 on UnderNet, is the younger brother of Sans and a major character in Undertale. He wants to capture a human so he can become a member of the Royal Guard.

Normal ("Battle Body")
Papyrus is a tall, perhaps anatomically inaccurate skeleton with a skull more vertical and geometric than his brother. Being skeletal, many of his expressions incorporate a toothy grin. His eyes lack pupils and resemble vertical slits; his skeletal pseudo-brows form most of his expressions.

He wears his "battle body," an outfit that he created for a costume party. It includes a white chest plate with gold trim, orange-red gloves with gold trim, blue briefs with a golden belt, and knee-high, orange-red boots. A symbol that resembles that of Starmen from the MOTHER series adorns the chest plate.

Befriending (Cool Dude)
Halfway through the date/hangout with Papyrus, he changes into his "secret style": a backward baseball cap, a t-shirt that reads "Cool Dude," small shorts with buttons, gloves with striped trim, knee-high socks, and sneakers. He also wears basketballs on his shoulders, likely Mettaton's MTT-Brand FashionBall.

Alphys Date (Jogboy)
During the "date" with Alphys, Papyrus arrives wearing a sweatband, shorts, and a t-shirt that reads "JOGBOY," with hearts on the pauldrons. He still wears his boots, gloves, and cape.

Personality
Papyrus is a flamboyant skeleton who presents a confident, charismatic image of himself. He works hard and, despite his brash personality, is kind at heart. He is optimistic and innocent even when the protagonist beheads him in a Genocide Route.

Papyrus is occasionally oblivious and nonobservant but can also be cunning at times, especially when he uses reverse psychology to trick Undyne into befriending the protagonist.

Papyrus believes in others just as much as he believes in himself. He has so much faith in his abilities that he waited outside of Undyne's house all night and begged her to accept him into the Royal Guard. Seeing his persistence, Undyne offered to train him but instead gave him cooking lessons.

He cooks spaghetti in his spare time, though many characters seem to think that he is not very good at it. One of the reasons for this is because Papyrus never ate spaghetti himself to complete the chef's guidebook to cooking by tasting their creation before serving. He, therefore, cooks spaghetti only because everyone else loves to eat it, indicating he does not play favorites. He loves puzzles and japes, as shown in the numerous puzzles he prepares for the protagonist as well as his collection of "complex tomes about puzzle creation." Though advanced puzzles may seem cerebral, Papyrus also enjoys children's books and is somewhat childish in his room decor. He also collects action figures.

Papyrus also watches Mettaton's TV shows, and Papyrus idolizes Mettaton so much that he would move to Hotland, a region that he dislikes.

Main Story
Sometime before the events of Undertale, Papyrus and his brother showed up one day in Snowdin and asserted themselves. Sometime after that, Papyrus became friends with Undyne and began training with her.

Neutral Route
Papyrus first appears in Snowdin Forest, where he proclaims to Sans that he will capture a human and become popular. Papyrus, ignorant of the human hiding nearby, berates Sans for not recalibrating his puzzles. Further in the forest, Papyrus meets the protagonist for the first time, though he initially confuses them for a rock.

Papyrus attempts to antagonize the protagonist with puzzles and japes, but he eventually warms up to them. He almost refuses to fight the protagonist out of pity. Though Papyrus initiates an encounter, he never kills the protagonist and instead places them in his shed if their HP reduces to one. The protagonist can easily escape his shed.

Ultimately deciding that the protagonist is friendly, Papyrus lets them continue into Waterfall, advises them on how to exit the Underground, and offers either a hangout or a date back at his house.

Returning to Papyrus's home after Papyrus's fight initiates the hangout or date. Papyrus dresses in his "secret style" and hides a special gift under his hat for the protagonist. Ultimately, Papyrus decides that the protagonist cares too much about him for their own good, and sends them back on their way with his phone number, which the protagonist can call at any time to hear his opinions about the room that they are in.

When the protagonist makes their way into Waterfall, Papyrus attempts to sway Undyne from killing them; Undyne refuses to yield, however, and Papyrus finds himself obligated to help her. He calls the protagonist and asks them to confirm what they are currently wearing. Papyrus is loyal to both Undyne and the protagonist by employing a ruse that backfires regardless of what the protagonist does.

If befriended, Papyrus calls the protagonist while Undyne is chasing them and say that they should all hang out. Backtracking to Undyne's house during the chase leads to the protagonist discovering Papyrus already waiting outside her house. After the protagonist chooses whether or not to give Undyne water in Hotland, they can go to Undyne's house, and Papyrus offers dialogue based on the protagonist's actions after his call.

He flees from the date early on, after using reverse psychology to get Undyne to befriend the protagonist.

True Pacifist Route
Befriending Papyrus is necessary to finish a True Pacifist Route. Flowey guides him to call all the protagonist's friends to New Home.

Before Asriel's boss battle, Papyrus rushes to intervene with the battle between Asgore and the protagonist. He then meets Toriel for the first time and becomes annoyed once she tells him a pun.

Flowey then restrains Papyrus and the rest of the monsters present with vines. Papyrus defends the protagonist from Flowey's bullets and states his faith in the protagonist.

Epilogue
Papyrus discovers that there is no need for the Royal Guard anymore and proclaims that this is " THE WORST POSSIBLE ENDING. " He also comments that Toriel is a " HUGE DORK. "

In the credits, it seems many of Papyrus's dreams have come true: he drives a red car along a highway, something he has always wanted to do. Later on, Asgore is shown trimming a hedge in the shape of Papyrus's face, something that Papyrus wished would happen once he became a famous royal guardsman.

Genocide Route
In a Genocide Route, Papyrus pulls much of the same antics that he does in a Neutral/Pacifist route, except often cites the protagonist's unwillingness to complete his puzzles. He remains oblivious to the protagonist's motives until their battle, where he instantly spares them, wishing to guide the protagonist on a better path and be friends. The protagonist can then spare or kill Papyrus.

If the protagonist kills him, he states he still believes in the protagonist and thinks that they can become a better person. If they decide to spare him, Papyrus proclaims that they " DIDN'T DO A VIOLENCE, " and says that he was secretly terrified of the protagonist. From that point on, the protagonist may choose to "hang out" with Papyrus, and the protagonist will abort the Genocide Route and move to a Neutral Route.

The Protagonist
Despite wanting to capture the protagonist, Papyrus still cares about them and eventually ends up dating/hanging out with them if the protagonist does not kill him. He turns the protagonist down if they choose to date, as he realizes he does not feel the same way about them. Notably, Papyrus will hang out with the protagonist even if they had been on a Genocide Route up until sparing him.

The protagonist remains friends with him throughout the game and gains the ability to call him on the cell phone almost anywhere.

Sans
Sans is Papyrus's brother, and though Papyrus often chastises him for being lazy and detests his many skeleton puns dropped throughout the game, the two of them care about each other a lot. Papyrus often cleans up after Sans and prompted him to get a job as a sentry.

Papyrus is upset that Sans naps so much and mentions that it's impressive how much slacking off his brother can do. Even though Sans reads Papyrus bedtime stories and is the sole provider in the skeleton household, Papyrus takes care of his brother and wonders what Sans would do without such a "cool guy" watching over him. Together, they made Papyrus's battle body as well as his cardboard sentry station in Snowdin Forest.

Papyrus also recognizes that Sans is secretive and kind of weird.

Undyne
Papyrus and Undyne are good friends. After Papyrus asked to join the Royal Guard, Undyne gave him cooking lessons, and they bonded. Because Undyne does not have the heart to tell Papyrus that she will never let him join the Royal Guard, Papyrus continues trying to impress her by capturing a human. Sometimes Undyne grosses Papyrus out, but Papyrus looks up to her as a role model. Papyrus is also oblivious of when Undyne is angry at him, though he is keen enough to know to present befriending the protagonist as a challenge to her.

Flowey
Papyrus sees Flowey as a good friend because Flowey offers him predictions, flattery, advice, and encouragement. Papyrus also borrows some of Flowey's dialogue characteristics, and Flowey guides Papyrus to call the protagonist's friends to interrupt Asgore's battle with the protagonist.

Trivia

 * Papyrus's pose is likely to be a reference to ancient Egyptian drawings which resemble his stance. Ancient Egyptians wrote primarily on papyrus, a type of paper.
 * Papyrus's name alludes the typeface in which he speaks in, Papyrus. This is a reference to Helvetica, which is a webcomic about a skeleton named after a font.
 * When attempting to name the fallen child "Papyru," the response becomes " I'LL ALLOW IT!!! "; as the character limit in the naming screen prevents Papyrus's full name to be entered.
 * Toby Fox has "deconfirmed" a claim that Papyrus was inspired by Octopimp.
 * According to Flowey, Papyrus's favorite food is "that oatmeal with the dinosaur eggs."
 * Despite his love for spaghetti, it is unknown whether he likes spaghetti himself since he has never eaten it before.
 * He is the only character whose dialogue does not begin with an asterisk.
 * He is also the only character always to speak in capitals (Mettaton stops talking in capitals when he becomes Mettaton EX).
 * Attempting to leave the electricity maze in Snowdin Forest will cause Papyrus to tell the protagonist not to be rude since he made the puzzle just for them. Backing away again causes Papyrus to ask if the protagonist treats their mother the same way when she makes them puzzles. Afterwards, he will just respond with " HUMANS... "
 * Doing this again during Sans's Monster Kidz Word Search puzzle prompts Papyrus to tell Sans that the human is escaping since he made the puzzle too hard.
 * There is a glitch where Papyrus speaks without using his font. Before the befriending event with Undyne, if the protagonist confirms the hangout from either side of Papyrus, speaks to the Dummy, then walks up to Papyrus from behind, this glitch will occur. Papyrus will speak in his font after Undyne answers the door, however.
 * If the protagonist walks in and out of Papyrus's kitchen before their date, he will run back and forth across the living room and offer differing dialogue based on how many times he did this.
 * Papyrus and Toriel are the only two characters without animated battle sprites.
 * When first seeing Undyne in Waterfall, when Papyrus comes in to give Undyne his report, if he was killed and the player moved left, they would still see Papyrus's sprite. This bug was fixed in the v1.001 patch.
 * Phone calls with Papyrus reveal the following information:
 * Papyrus has an imaginary store that sells flames. It is "a dream of [his]."
 * Papyrus does not remember Napstablook's name and tries to guess it if the protagonist phones him outside their house. His guesses are "Spooky Bloo Bloo" and "Napper Hog." He also does the same with Flowey, except saying "Flowery", and with Napstablook's cousin, calling him "Happstablook".
 * Papyrus believes skeletons are warm and cuddly, but that ghosts are spooky.
 * The snails of Blook Family Snail Farm remind Papyrus of his brother.
 * Papyrus would try eating the mushrooms in the room before the darkening lantern room and the lanterns in the darkening lantern room.
 * Even though he's never seen it before, Papyrus disdains anime.
 * Papyrus says that Undyne enriches his life with shed-based puns.
 * Conveyor belts and lasers are his least favorite nightmare.
 * It is implied that Papyrus's "special attack" involved a Gaster Blaster.