King Asgore Floribus Ignis Dreemurr

King Asgore Dreemurr.

Asgore is a Boss Monster, that resembles a great goat or a lion, since it owns a mane blond and legs besides two great curved horns unlike its ex- wife.
He wears an armor, as well as a purple cloak and yellow shoulder pads. He is of great and intimidating stature, from time to time he wears a small crown that he wears on his head with something similar to a stone or gem, and he has a big red sword under the name of "Höfund".
Asgore begins being kind and gentle, but when he is in combat he takes a more serious and repentant attitude in battle to get the seventh soul, but with much shame.
He is represented as a kind and tolerant family man; This is shown through his dialogue with Frisk during his meeting on the Neutral and Pacifist Route. In your attempt to be as kind as possible despite knowing that you will ultimately have to take your soul, going so far as to make a small talk.
Based on King Arthur for nobility and kindness. Although both have stumbled on their journey through wisdom.

Sir Papyrus the Noble

Papyrus at the end of the wooden bridge.

Papyrus is a tall skeleton, with a more straight and geometric skull structure (in contrast to his brother's skull, which is rounder). His mouth is shaped like a smile most of the time, it is very expressive, especially with his eyes, since he can only move the corners of his mouth like his brother.
He wears a handmade armor that he calls his "Battle Body", which is composed of a white piece with gold edges, a red scarf around the neck, red gloves (with gold edges), blue underpants with a golden belt, and high red boots. His armor was created with the purpose of attending the meetings of the knights (which he did not receive any invitation) and has used since then. He carries with him two axes of toy with the edge of orange and blue, also he wrote the name with marker the words Leviathan 1 and Leviathan 2.
Papyrus is a noisy and extravagant skeleton that shows a sure and charismatic image of himself. He tends to be a worker and despite his bold personality, he is a good-hearted skeleton. He is extremely optimistic and innocent, even when in danger he always believes that everyone can be good if he tries. Sans is the older brother of Papyrus, and despite always reproaching him for stopping being so lazy and making so many bad word games, the two take great care of each other. Sans refers to his brother as "cool". Papyrus frequently cleans up what Sans leaves, saying that "Sans is fortunate to have a great brother who takes care of him." It was Papyrus who convinced Sans to get the guard post on the outskirts of the Ruins.
Papyrus, occasionally, acts unconsciously and distractedly, as well as when he tries to smear different creams and "sauces" behind his ears, only to realize that he has no ears. Sometimes he shows ingenuity, which is denoted by using reverse psychology to make Undyne make friends with the fallen human.

Sans the Skeleton

Sans in the Judgement Hall

Sans is the older brother of Papyrus. It appears at the beginning of the Snowdin Forest, located on the outskirts of the village of Snowdin, giving a small scare to the fallen human due to the sounds it makes when it approaches it. Depending on the Frisk's choices, he can be both a friendly character and an ally, as well as a heroic antagonist.
Sans is a skeleton of short stature and large bones, dressed in a coat with a fur hood, black pants with a white line on the sides, a chain mail and black boots and is always carrying a bone larger than him, pretending to be a staff or a spear without a tip.

He is always seen with a smile and only moves the corners of his mouth a little. He has white pupils that tend to disappear when he speaks in a serious tone. A bright and intermittent iris of blue and yellow colors appears in his left eye during the battle against him on the Genocidal Route.

Sans makes his scythe appear.

He has obtained the knowledge of the multiple lines of time and the function of the SAVE, apparently through his scientific investigations. He seems to have knowledge of when the Frisk loads a SAVE file, although he can not use the SAVE function himself. However, he does not seem to be able to remember what happened when doing a RESET, although he can recognize when the player has made one. Apparently his knowledge of the situation and his innate perception allows him to recognize when the fallen human has been behaving in an unusual way.

Lady Toriel

Lady Toriel

Lady Toriel is the Guardian of the Ruins, the ex-wife of King Asgore Dreemurr, adoptive mother of Chara and biological mother of Asriel. Before the events involving Frisk, Toriel was queen of the Underground, wife of King Asgore, and biological mother of Asriel.
One day, a human falls into the Underground. Toriel's son, Prince Asriel, takes her with her and is treated as part of the family. Later, the human becomes seriously ill. The next day, he dies. Asriel uses the soul of the human to leave Mt. Ebott, entering a nearby town and places the body of the human on a plain of Red Flowers that grew in the center of town. The humans of the town thought that Asriel had assassinated to the infant and it had attacked it with everything what they had until finally, Asriel dies crossed by a spear in the side. Asriel returns wounded to the Underworld, where he finally collapses in the throne garden and dies falling into dust on the flowers.
In an attack of rage and sadness for having lost two children in one day, Asgore declares war on humans, but Toriel does not accept this behavior and chooses to retire to the Ruins. She receives another six humans, and all fulfilled the same fate; They left the Ruins and were killed. For a long time, Lady Toriel has forged the armor of the other six fallen humans, based on the personality or trades of each one. By the time the seventh Human, Frisk, came to the Underground, she had created an armor without knowing anything about it and placed it on a stone at the entrance to the ruins.

Noble Knight Frisk

Noble Knight Frisk

Frisk the human, is a direct descendant of the leader of the Order of the Seven Virtuous (that were conformed by the humans that banished the monsters).
His story begins when he explored the forest surrounding Mt. Ebott, after entering a gloomy cave, accidentally he stumbles on roots and falls into a dark circular hole, landing on a bed of red flowers.
When he wakes up, he goes deeper into these mysterious caverns with stone pillars that adorned the walls and supported the ceilings, on the way he encounters a mysterious armor placed carefully on a stone, the colors of the armor are blue with purple details and with a big heart made of Ruby in the center. Thinking that there would be danger later on, he does not hesitate for a second and he puts it on, which coincidentally is  his size.
In the darkness of that mysterious place, a red flower appears that speaks that he calls himself Flowey the Flower, then he meets Lady Toriel, she guides him through the ruins of the subsoil, where her later lodges him in her house .
Lady Toriel offers a room and the comforts of home, but Frisk asks for to return to the surface, so Toriel will try to destroy the exit of the ruins to protect him from King Asgore, who according to her, is a tyrant. The fallen human rejects her proposal and she has no choice but to destroy the only exit that takes him out of the ruins. Here Frisk will have the option to kill her or convince her to let him go.