Papyrus is a tall skeleton wearing an orange hooded jacket and beige shorts. He also wears orange (but is sometimes drawn wearing slippers) shoes with white laces and is often seen smoking, in fanarts and sprites of him.
Papyrus is a calm, lazy and even fun character, but he can become very serious in situations that require it. Although his brother Sans is not happy with his vague attitude. Papyrus is considerate, as well as having lots of respect. Papyrus is quite protective of his brother despite his chill attitude and his brother's hate for his jokes.
Papyrus has the ability to dodge attacks, and excels in combat and fights with unique abilities that include: Karmic Retribution, changing the effect of gravity on the SOUL and attacking the protagonist in the selection menus. He can also invoke Gaster Blasters, which are unique skulls firing a powerful Spaghetti beam, as well as having telekinesis and the unique ability to know of the RESET and its effects. Like Sans, his powers mostly involve bones and Gaster Blasters, and is more tense than the other battles in the game. Papyrus is the most difficult opponent of all the enemies in Underswap.
Karmic Retribution is like poison, it is left on the player everytime they hit an attack from Papyrus. It is very difficult to get off and its better to use food then waiting for it to leave. In Papyrus' battle, it replaces the HP having it say KR.
Papyrus meets the protagonist after they enter Sunnedout forest. Like Undertale Sans, he tells them to hide from Sans who berates Papyrus for being lazy and smoking. He then follows Sans around mostly in their puzzles for the protagonist. However, in Sunnedout Town he is completely absent.
Papyrus will meet the protagonist again in the entrance of Firerise; But if the protagonist kills Sans, Papyrus will not appear anywhere else apart from the Judgement hall, which is also his last appearance.
If Sans is spared, he then invites the protagonist to Muffet's and have a snack. He also asks the protagonist about a talking Temmie and whether or not they saw them, because the temmie is always giving Sans advices and warn them to keep an eye out. After that, Papyrus will go back to work. When Alphys is chasing the protagonist to Hotland, Papyrus is found sleeping in his job again which annoys Alphys and gives her a period to stop.
Papyrus then can be found in the middle of Hotland selling Hot Cats, and will give the protagonist an actual hot dog if the protagonist goes on for a second time. If their inventory is full, Papyrus will stuff 30 hot cats on top of their head for free. Furthermore, in NTT Resort entrance, Papyrus will invite the protagonist for a snack and say that he met an old man who enjoys puns and constantly made them. The old man then wanted Papyrus to keep a promise to not harm any human, which is why Papyrus doesn't attack the protagonist at all in the Neutral route even if they already killed Sans.
After an absence in the CORE, Papyrus makes his last appearance in the Final Corridor judging what the protagonist has done so far.
"YOU DIRTY BROTHER KILLER." — Papyrus if the protagonist kills Sans in the neutral route
Papyrus will judge the protagonist's actions before this moment. If the protagonist spared everyone, Papyrus will praise the protagonist instead and tell them to keep it up. He then tells tips to the protagonist whether they should take Toriel's soul or let Toriel take their soul to escape the barrier.
- If this happens the second time, Papyrus will notice that they are bored of the same words. So if they load their SAVE a few times, Papyrus' suspicions are confirmed and he gives them a key to his room. Inside his room is a key to his workshop.
If the protagonist gained a few EXP by killing anyone other than Sans, Papyrus will let them think about their actions for a moment. If the protagonist killed Sans, Papyrus expresses his suspicion that they have some special power. He then asks if the protagonist thinks it is their responsibility to do the right thing. Regardless of their answer, Papyrus reminds the protagonist of his late brother and leaves.
True Pacifist Route
Not much difference is made at the beginning of the protagonist's journey. However, he skips the judgement because the Protagonist spared everyone. He is one of the major characters who appears in the True Pacifist Route, later being trapped by Temmie who then absorbs all of the SOULS and becomes Monster Kid.
There is a big difference compared to Neutral Route. Unlike Sans, Papyrus is completely aware of the protagonist's aggressive side. Just like he does in the Neutral route when Sans is killed, he makes his last appearance before the entrance to Snowdin Town, warning them not to kill Sans. If the protagonist does kill Sans, he will teleport to the Final Corridor; if the protagonist spares Sans, the game will switch to the neutral route, and Papyrus will appear in the entrance before Firerise. He will not invite them to Muffet's, since there is no one in Sunnedout.
In the Final Corridor, Papyrus skips the judgement hall, and proceeds to break his promise with Asgore and fights them. Papyrus says that not even getting to the surface will help anymore, and how he is tired of the protagonist being aggressive. If the protagonist stops fighting him and spares him, Papyrus traps the protagonist by hugging them and summoning bones to kill them. If the fight goes on, Papyrus will show them his special attack, which is nothing and the protagonist can therefore no longer attack, as it will never be their turn to. The protagonist will still fight him, and in one hit Papyrus will die. After that, he says he is going to Muffet's, before he dies and turns into dust.
Papyrus starts his attack with a series of Skull-like Gaster Blasters, shooting a orange/red beam of energy towards the player, and a bone wave which you have to dodge in order to survive. Papyrus states (If you manage to survive after that) "Huh.That's why you don't use your strongest attack first". After that, Megalotrousle can be heard during the fight. Papyrus has a orange/red glowing eye which controls the gravitation of the player, and can summon Gaster-Blasters. Near the middle of the fight, he "Spares" you. If you accept, You get "dunked on". On the other hand, if you continue to fight, he states that, "It was worth a shot".
Papyrus's attitude towards the protagonist depends on their actions, though he usually enjoys pranking them and occasionally hanging out with them unless they kill Sans. Near the end of a Neutral Route, he judges them on their EXP. At the end of the True Pacifist Route, Papyrus considers them a good friend.
Papyrus initially considers the protagonist to be an "anomaly"; his intentions of befriending them were in the hopes that they would stop resetting the timeline. However, he also says that the only reason he did not kill the protagonist after their initial encounter is because of his promise to Asgore.
Papyrus cares for and admires his brother. He reads him bedtime stories and gives him presents under the identity of Santa. Nonetheless, Papyrus hates Sans's bad puns. He also leaves a dirty sock in their living room for Sans to fuss over.
Papyrus worries about others hurting Sans or taking advantage of him. In some Neutral Endings, Papyrus is afraid to tell Sans about other characters' deaths, so he lies about them going on a vacation.
Asgore and Papyrus are friends even though they never see each other face-to-face until the epilogue, the Family Ending, or the Exiled King Ending. Before the protagonist's arrival, Papyrus and Asgore talked to each other through the entrance door to the Ruins.
In the Exiled King Ending, Papyrus may become Asgore's roommate if Sans has been killed. In this route, Papyrus also states that he "can't bear to tell him what the protagonist did." If Sans is alive, the brothers visit Asgore often, play board games together, and sometimes convince Asgore to leave the Ruins.
While not being one to make promises, Papyrus complies with Asgore's request to watch over and protect any human that exits the Ruins. At the end of the Genocide Route, he indirectly apologizes to him, as he is forced to break his promise to stop the protagonist.
Though there is evidence that Papyrus and Undyne have a relationship, Papyrus only alludes to this in the epilogue.
A few things hint at a connection between Papyrus and River Person. Evidence includes the blueprints and veiled machine found in his workshop, the sprites used for his skull-like laser guns, and his unexplained scientific research on the "anomaly" and timelines.
- Underswap Papyrus is protective of his brother, Just like Undertale Sans.
- Papyrus likes sharing bad jokes with Asgore.
- He has incredible dodging skills like Undertale Sans.
- He wears similar clothes to undertale Sans and Underswap Sans wears clothes similar to Undertale Papyrus.
- Underswap Papyrus has a bad time form, like Undertale Sans.
- Underswap Papyrus sells corndogs in different places of the underground
- While Undertale Sans drinks ketchup, Underswap Papyrus drinks honey
- Like Undertale Sans, his attacks are Karmic Retribution.
- Papyrus isn't the kind of person to make promises, but he made one with Asgore to watch over any human that exits the Ruins. The only time he breaks this promise is when the Protagonist does the Genocide Route