Kris Dreemurr is a non-binary human teenager that only goes by they/them, around 15-16. They have an amber skin tone and shoulder-length dark maroon hair with long bangs. They wear a long-sleeve lime hoodie with one horizontal yellow stripe, and brown 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 their SOUL out of their body, their red eyes can glow in the dark. When deprived of their SOUL for long periods of time, Kris's skin shifts into dark green hue with their movements becoming limp and weak. Their SOUL is a red, sentient non-verbal heart that when it is inside them, it controls their actions and glows in the dark. Kris is mentioned to be an introvert. Susie refers 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.

Toriel Dreemurr is a goat monster whose head resembles a white-furred Nubian Goat, structured with floppy ears and tiny horns. She has a pair of visible fangs and long eyelashes, and her irises have a dark red tint. She has an anthropomorphic body, with paws at the end of her limbs. She has a small tuft of fur on the top of her head, and does not wear her distinct Delta Rune tabard. Instead, she favors casual clothes, which consists of an iris long-sleeve jacket, a black blouse, and a polka-dot skirt. She also wears a heart pendant and color matching glasses. She has a kind and motherly temperament, as she is a parent to three kids: Asriel, Kris and Guest; and is a teacher for the younger students at the local school. She is tidy and old-fashioned, as her house has a landline telephone, as well as a television with an external antenna; her interests include baking, teaching, reading, snails, and puns. Toriel is religious and keeps a book of hymns in her home and frequently attends church. She is also prone to being judgmental. She appears to expect trouble from Kris since she recalls their past mischief, such as the time they put a bath bomb in the toilet, and emphasizes that Kris should not consume all the pie. Toriel knows how to drive a car, and takes Kris and Guest to school instead of the school bus.