Papyrus wears a grey t-shirt and plain grey shorts, as per UMH regulations (though he was able to convince Toriel to let him put 'Cool' in bright red letters on the chest of his shirt). He may also wear his signature red scarf, with his boots and gloves. Occasionally he will be wearing something else (like his 'Battle Body', or a new outfit), which were gifts from Gaster.
Papyrus is rather bubbly despite his circumstances, and can usually be found talking with others in UMH. Most of his happiness comes from his father, Gaster, who regularly visits and reassures Papyrus that he'll be let go someday.
When Frisk arrives his shy side rises up and he doesn't talk as much, though this can be changed if a Pacifist Storyline is followed. If not, he can become aggressive and/or reclusive.
Papyrus has a very good relationship with his father. The two of them spend a considerable amount of time together, as Gaster does regular research at UMH. Sometimes Papyrus will even accompany him when he does his research, and Gaster plays along to keep his son happy. When Gaster tells Papyrus he has to leave, things don't end very well. He may start crying and begging as a guilt-trip to keep his father there, or his inner demons might sense a chance to send him into a 'Schizophrenic Break'.
Papyrus looks up to his brother. When Sans comes to visit, either with Gaster or on his own, Papyrus clings to him like a life raft. Sans doesn't really mind, enjoying the closeness. When Sans prepares to leave, however, Papyrus reacts the same way with Sans as he does Gaster.
At first Papyrus is wary of Frisk, and tries to avoid her whenever possible. As time wears on, however, Frisk is finally able to open him up. This is something Papyrus very much needed, but would never let happen. After opening up to Frisk, Papyrus seems calmer. He can more easily control his emotions and his inner demons don't seem as frightening. Despite Frisk being a positive influence on his mental health, though, Papyrus still goes into a Schizophrenic Break every so often.
Papyrus' relations with Frisk depend on who Frisk speaks with and how she speaks with them in the Neutral Storyline. If she speaks with him and his friends respectfully, he will have great respect for Frisk and act much like his Pacifist Storyline counterpart. If not, Papyrus may speak to Frisk with a harsher, more rude vocabulary, refuse to talk to Frisk completely, or even attempt to harm her.
In the Genocidal Storyline, Frisk will speak disrespectfully to Papyrus and his friends. This may trigger him to act violently towards her (on Flowey's suggestion), or for him to tell Gaster and Sans, who will in turn act against Frisk. If neither of these events occur, Papyrus may simply go off and hide in his room and refuse to come out. This would trigger other characters (such as Undyne or Alphys) to act against Frisk.
He and Undyne are decent friends, and occasionally Undyne will visit him when she's not with Alphys.
Papyrus and Alphys only know each other through Undyne, but tend to get along even when she's not present. The two of them both like to cook, and do so on a regular basis, even coming up with new recipes for their favorite dishes.
Although he doesn't know Mettaton well, Papyrus aspires to have the self-confidence and pride that said robot does (or appears to have).
Papyrus is terrified of Flowey. Said flower uses this to his advantage and scares Papyrus into doing many things he normally wouldn't do. However, this may send Papyrus into a Schizophrenic Break, where he will act in spastic ways to try and get Flowey out of his head.
Papyrus likes to be around the Temmies that work for Asgore and Toriel, as they're always happy and ready to give out hugs. He doesn't know any of them very personally, but has come to see them as a sort of extended family.
Papyrus feels that Asgore is his second father. When not doing anything around UMH, Papyrus may be found at the main desk with Asgore, simply talking or asking how other patients are doing.
Papyrus adores Toriel. The two enjoy tending to Toriel's flowers and making up stories. If Papyrus is having issues and Gaster isn't there, Toriel will be the first person he goes to.
Papyrus would consider Lucario one of his best friends, even though he can be timid at times. Papyrus likes drawing pictures for Lucario, and will often slide them under his door.
Papyrus isn't quite sure what to make of Bob. He enjoys Bob's seriousness from time to time, but feels that said Temmie doesn't have enough fun in his life. Because of this Papyrus tries to draw pictures for Bob that would make him smile and/or laugh.
Papyrus is terrified of Calibri, like he is of Flowey.
Reason for Admittance
Papyrus was admitted into UMH because of an unexpected hospital visit, said visit being the result of Flowey's torture.
~More Information Coming Soon~