Dess is a cool, mysterious, playful, and teasing dark-haired deer monster. Standing at 5'8", she has a biker-type fashion sense, preferring jeans and stealing Asriel's clothes over skirts or tight pants. She's a typical teenage girl who loves playing guitar, listening to rock and goth music, and has a habit of smoking. Despite her rebellious exterior, she is deeply caring, especially towards her younger sister, Noelle. Her bold and playful side comes out strongly around her crush, often teasing him. Despite being called dess her full name is December. She has a fer ear piercings and one eyebrow piercing despite Carol's protest.

A young reindeer monster with short light-brown fur, a bright red nose, freckles, small antlers, and long golden-blonde hair. She typically wore a red-and-green checkered sweater with dark sleeves and a dark skirt (or similar casual clothes). Kind, cheerful, and extremely timid. Soft-spoken and easily frightened, she cried when scared and developed a fear of humans under her bed thanks to Kris’s pranks. Despite that, she remained sweet and patient toward them while staying very close to her sister Dess.

An adult reindeer monster with pale beige/ash-blonde fur, light blonde hair, blue antlers, blue eyes, and a blue nose. She carried herself tall and composed, usually in neat, formal-leaning clothes (such as a cardigan or blouse with pants). Firm, no-nonsense, and authoritative, but less cold than she later became. She had a sharp temper (once slapping Rudy hard enough to knock him out) yet still joined the Dreemurrs for holidays, festivals, and TV nights, often light-heartedly annoyed by Toriel’s energy and Kris’s antics.

A small human child with yellowish/amber skin and messy brown hair that partially covered their eyes. They usually wore a long-sleeved green shirt with a single yellow stripe and plain pants. For a while they also wore a red-horned headband, hoping to look more like the monster kids around them. Quiet and mischievous, Kris often felt like an outsider but stayed close to Asriel and the Holiday siblings. They loved pulling dark pranks (especially on Noelle), playing piano for hours, and exploring the woods. Despite being way younger than Dess kris has that kid crush that every kid has on someone older.

An adult goat monster with white fur, long floppy ears, small horns, and a soft, motherly face. She dressed casually but neatly—often in a light purple jacket or blouse with a skirt—and sometimes wore glasses. Warm, protective, and lively beneath her traditional exterior. Deeply caring toward Asriel and Kris, she enjoyed baking, family routines, and church. In college she started out reserved at parties but quickly became energetic and fun.

Rudy Holiday is a warm, jovial reindeer monster and the bedridden father of Noelle and Dess. Currently hospitalized with an unnamed but serious illness, he spends his days in a hospital bed cracking jokes, playing video games with his daughter, and using humor to keep her from worrying about him. Despite coughing when he laughs too hard, he remains lively, protective, and lighthearted—teasing Noelle about her crush on Susie, playfully calling Berdly “Nerdly,” and treating visitors like Kris with easy dad-energy and card-game challenges. He is married to Mayor Carol Holiday and is Asgore’s longtime best friend from their college days.

Asgore Dreemurr is the large, white-furred, goat-like former police chief of Hometown and the father of Kris and Asriel. After an unexplained incident cost him his job and contributed to his divorce from Toriel, he now lives alone in the back of his struggling flower shop, “Flower King,” where he tends plants and gives away bouquets more often than he sells them. Affectionate but often awkward and overly eager, he still clings to hope of reconnecting with his family while quietly carrying guilt and loneliness. He remains close friends with Rudy Holiday (who was his best man at his wedding) and regularly visits him in the hospital with flowers.