Dreemur is a human 18 year old. In the Light World they have amber skin tone and shoulder-length dark maroon hair with long bangs. They wear a long-sleeve lime shirt with one horizontal yellow stripe, and nondescript pants and shoes. One of Kris's distinct traits is that their long bangs cast a shadow that hides their eyes. In the brief moments they tear the SOUL out of their body, their red eyes can glow in the dark. One of their crimson eyes is also visible for a few frames when they descend into a Dark World. Kris is grumpy and tired and usually crude despite being flirtatious at times. They are quite creepy sometimes due to their lack of social skills. Kris is adopted by two anthropomorphic goats, Toriel and Asgore and has an adoptive brother which is Asriel. Kris is also friends with Susie, a tall purple anthropomorphic reptile.

During the events of Deltarune, Kris is mentioned to be an introvert. Susie and King refer to Kris as a "quiet person," and Noelle is astonished if they converse about "anything." After Kris's brother, Asriel, left for college, they became distant from their few friends. Kris's side of their shared bedroom is also strikingly bare. The shared game console is underneath Asriel's bed, and their old children's books are in Toriel 's classroom instead. Toriel has also mentioned that Kris is not normally energetic. They have a history of not waking up on time, and often slept through the start of class Kris also preferred their mother driving them to and from school than walking.

Contrary to Kris's apparent detachment, they do have a variety of interests. Kris has always been mischievous, pulling dark pranks such as covering themself in ketchup and claiming it was blood. For example, Kris has the option to keep flushing the toilet before or after going to school, with Toriel replying: "You did not put a bath bomb in the toilet again, did you?"

Kris enjoys playing the piano. Prior to the game, they frequently played the hospital piano, despite it "missing most of the good keys." They have searched for tutorials to improve, and Red Big Mouth believes they can play the hospital piano "beautifully." In a private post from Noelle's blog, Noelle mentions that Kris would often come to her house and use her piano since Kris did not have one in their home. Noelle explains that whenever she followed them into the dining room to listen to them play, Kris would immediately stop playing. Without an interruption from Noelle, however, Kris would continue playing, sometimes for hours at a time.

When younger, Kris studied the occult with Catti. They appear to still have an interest in this topic, as one of their search queries was "how to use magic."

At the end of Chapter 1, Red Big Mouth and Toriel both comment on Kris's physical appearance. They cite that Kris seems "a little sick" and does "not look quite yourself" respectively. It is implied that the SOUL is the reason, though the exact cause is unknown. Notably, Kris wants to be perceived as "normal" despite Toriel's concern.

Kris is shown to have a significant amount of agency outside of the player's choices when in the Light world. This is most clearly shown in scenes where Kris rips the SOUL out of their body, but also in how characters react to Kris's dialogue choices: occasionally, the player may choose an option that other characters note sounds like Kris is straining to say. Kris is also shown performing actions independently of the player's control, including protecting Susie from King or awkwardly trying to escape the Sweet Cap'n Cakes fight with Ralsei and Susie, showing their friendship with the two exists outside of the player's influence. Additionally, there are some instances in Chapter 2 where Kris stops inspecting something relating to their home life, preventing the player from learning more: when inspecting Asriel's room in Queen's Mansion, Kris closes their eyes before peeking into Asriel's room in the Guest Hall; when inspecting an article about Asgore's firing and Undyne's promotion, Kris intentionally stops reading before the reason is given. The separation between the player and Kris is most clearly shown in the Weird Route, where it is heavily implied Kris's actions are being done against their will. Noelle describes the voice she heard giving her orders as terrifying, noting Kris has been acting very strange lately. When Kris reunites with the party after defeating Berdly, Susie and Ralsei immediately notice Kris appears distraught.

Another instance of this happens in the normal route of Chapter 2, where after defeating Spamton NEO, Susie notices Kris appearing to be in shock. If the player responds to Susie that they're okay by saying Yes, Kris appears strained in their response, making Susie think that they're not okay; if the player responds to Susie by saying No, Kris yells out the response, concerning Susie and Ralsei. This heavily implies that Spamton's dialogues about being a puppet and cutting his strings to be free, combined with Spamton's ultimate fate, deeply unsettled Kris.

Years ago, Kris was adopted by the Dreemurrs and grew up in a loving family. However, as the only human child in Hometown, Kris often felt like an outsider. Kris once asked their adoptive parents when their "horns were going to grow in." In response, Toriel and Asgore bought a headband with red horns for Kris, who wore it for months.

Growing up, Kris became very close with their older brother, Asriel. The two often explored the forests around town with their neighbors, Dess and Noelle Holiday. While Kris went over to the Holiday residence and played with or pranked Noelle, they would go to play the piano but stop if Noelle was watching. The four were close friends, Kris and Noelle grew apart over the years. The cause for this is unknown but is implied to have been related to Dess subsequent disappearance. Kris had also wanted to befriend Bratty, as she was one of the "big kids." They willingly complied and retrieved food for her until she became sick.

At some point, Toriel and Asgore became divorced. It is implied in Chapter 3, that prior to the divorce Kris witnessed various arguments from their parents leaving them distressed. It is also heavily implied in the Egg segments that Kris went through some sort of traumatic event that they repress, given that interactions with the Man point to something they saw behind a tree that they cannot bring themself to fully see or draw out. While their family was broken, Kris and Asriel remained inseparable. On occasion, Asriel would buy Kris a hot chocolate at QC's Diner, something they used to do together as a whole family. One day, Asriel had to go away to college, leaving Kris alone and without many friends.

Susie: Susie is 19 years old. She appears to be a tall, purple, lizard-like monster with messy aubergine hair and clawed hands. She has large eyes with yellow sclera, freckles at the sides of her face, and yellow fangs. Her attire consists of a long purple cardigan, a white trimmed light blue shirt, a pair of torn jeans and a pair of black shoes. During most of Chapter 1, Susie's eyes are hidden behind her hair, outside of certain sprites and dialogue portraits. After Kris protects her from King's attack, she uncovers them and often keeps them visible. Susie is known for being rude, vulgar, as well as making sarcastic or brutally honest remarks. She can threaten with physical violence, such as biting off someone's face. In a Dark World, she is willing to attack Darkners if they are perceived as enemies. However, Susie has a different temperament to those who are kind to her. With friends, she is expressive, willing to talk about herself, and ask for their opinions. Susie favors teasing her friends, and is more observant of their emotions. She makes an effort to be considerate, and tries to not push them to talk about a stressful issue. Susie is also loyal, readily wanting to assist a friend if they are in danger or troubled. She likes compliments, and is easily flattered. Susie also enjoys causing mischief and childish antics, such as trying to fit in a freezer. She appears to like eating in general, including non-food items (most notably chalk), and receiving gifts. She is possessive of items given to her. In susie's Dark World room, her fridge has multiple non-food items she likes, which shows that susie really enjoys eating them. Susie is implied to have self-esteem issues. She used to think that nobody liked her before she found real friends. She is also aware that she struggles academically. Susie can also occasionally project onto others. Susie seems to fall asleep easily, as evidenced by the use of the Sing command in the battle against her and Lancer, and at the end of Chapter 2, where she falls asleep almost immediately after she and Kris sit down and start watching television. Even after befriending Kris and Ralsei, Susie is still shown to very much enjoy FIGHTing. This is best shown when “defeating” the Knight, Susie say they were only getting started, and even attempts to engage with them again. Susie had a rough past, struggling to make friends, and moving away whenever she did. It was when she got to Hometown Toriel found her alone, sitting on a bench in the graveyard crying, who told her it would be okay, and got her food at the diner. Susie still resides in Hometown and attends the same class as Kris and Noelle, having arrived as a new student at some point.[4] She is close to getting expelled from School due to unknown past incidents.[5] She is universally feared among her classmates and even by Alphys, due to her appearing to be a threat. Monster Kid described her as creepily watching them and their friends playing handball. At one point, the ball rolled over to her, causing her to freeze and kick the ball as hard as possible at Undyne's car. Little else is known about Susie's history prior to the events of Deltarune.