Toriel

Toriel (/ˈto.ɹiː.ɛl/, TOR-ee-el) is the second major character the protagonist encounters in Undertale. She saves the protagonist from Flowey and guides them through the Ruins.

Appearance
Toriel is a Boss Monster whose head resembles a white-furred Nubian Goat, with droopy ears and short horns. She has a pair of visible fangs and long eyelashes; her irises have a dark red tint. She has an anthropomorphic body, with paws at the end of her limbs. She wears a long purple robe that displays the Delta Rune on her chest and is occasionally seen with her reading glasses on.

Personality
Toriel is a kind monster that acts as a protective mother for the protagonist; she employs tough love on the protagonist as well as Asgore. She cares for children and was excited to be a mother herself.

She enjoys cooking and bakes butterscotch-cinnamon pie as well as her favorite, snail pie.

Toriel has a playful side and loves puns and bad jokes, and she even keeps a journal of puns.

Toriel is intelligent and dreams of becoming a teacher. She has already prepared a curriculum for the protagonist by the time they reach her home in the Ruins. In True Pacifist Ending Credits, she stands outside a school and, in the Family Ending of a Neutral Route, she starts her own.

Main Story
Before the events of Undertale, she was married to King Asgore and had a son, Asriel. When the first human fell into the Underground, she adopted them as their child. The deaths of their two children pushed Asgore to declare war on humanity, and as a result, she divorced him, abdicated her throne, and retreated to the Ruins.

Between then and the time the protagonist enters the Underground, she sees multiple humans be murdered and their SOULs reaped by Asgore.

Neutral Route
At the beginning of the game, Toriel saves the protagonist from Flowey, healing any damage done by the murderous flower. After introducing herself, she guides them through the first few rooms of the Ruins. She encourages the protagonist to deal with monster encounters by talking to them, as opposed to acting violently.

She gives the protagonist a cell phone to keep in contact with one another, as she needs to run some errands further into the Ruins. She tells them to stay where they are, only to be disobeyed. She calls the protagonist frequently as the protagonist goes through the Ruins, and is about to call them again when she finds the protagonist at the entrance to her home.

She introduces the protagonist to their room and plans to raise them as her own. After the protagonist asks her about leaving the Ruins, Toriel abruptly leaves; the protagonist follows.

As she goes toward the exit of the Ruins, she explains that she plans to destroy the exit to prevent the protagonist from leaving, as all other humans who left had died.

At the end of the Ruins, Toriel tells the protagonist to prove themself strong enough to survive and fights them in a test of strength. She can be killed or spared; if spared, Toriel lets the protagonist go but tells them not to come back.

Sans tells the protagonist during their rendezvous, that he and Toriel have been friends for a while, bonding over their love of jokes and puns. Neither of them knows each other's name or face, as they communicate through the door that blocks off the Ruins.

Sans also says that Toriel asked him to protect any human that left the Ruins. He remarks that if not for that promise, the protagonist would be " dead where [they] stand. "

True Pacifist Route
Toriel reappears just as Asgore and the protagonist prepare to fight, interrupting it with her fire magic, much like she does with Flowey at the start of the game. She explains the motive of her arrival was the realization that the protagonist would have to take a life to leave, and that she was trying to prevent such thing from the beginning.

As the protagonist's friends come, she introduces herself to them and recognizes Sans's voice immediately. She tells the protagonist that while they may have to stay Underground with all their friends, they will live a happy life regardless.

Flowey then appears. Having absorbed the human SOULs, he binds Toriel and company with vines. When Flowey tries to kill the protagonist, Toriel is the first monster to intervene, using her fire magic to block Flowey's bullets. Her SOUL, along with every other monsters', is eventually absorbed by Flowey, allowing him to become Asriel.

During the protagonist's battle with Asriel, Toriel appears as one of the Lost Souls.

Epilogue
After the fight against Asriel concludes, she learns the protagonist's name, "Frisk." She tells them that they are free to go through the Underground to talk to more of their friends. Meanwhile, Alphys upgrades Toriel's phone, allowing her to send text messages.

Frisk leaves the Underground with Toriel and their other friends. As the others leave Frisk to begin their lives on the Surface, Toriel asks Frisk what they will do now.
 * If Frisk decides to stay with Toriel, she says that none of this would have happened and that it was for the best that they decided to leave the Ruins. She then promises to take care of Frisk for as long as they need. Like in the Ruins, Toriel takes Frisk's hand as they walk offscreen together. After the credits, Toriel brings a slice of pie to Frisk's room.
 * If Frisk says that they "have places to go," Toriel says that she will see them later. After the credits, Frisk and their monster friends are shown together in a sepia photograph.

In the credits sequence, Toriel welcomes the Monster Kid to a school that she opened and teaches at. The school door is adorned with the Delta Rune sans the triangles that represented the monsters trapped Underground.

In Battle

 * See Toriel/In Battle

The Protagonist
Toriel cares for humans who fall into the Ruins, and the protagonist is no exception. She tries to keep the protagonist in the Ruins, as Asgore killed the other humans who left her care. If the protagonist spares her, she lets them leave the Ruins, but not before giving them a parting hug.

If the protagonist kills her during a Neutral Route, she uses the last of her strength to give them a warning about what lies ahead and calls the protagonist "my child" before she turns to dust. If the protagonist kills her when she offers mercy, she says that the protagonist is like the monsters outside the Ruins. In the Genocide Route, she realizes that the protagonist is dangerous and laughs hysterically before she dies. The death sprite for Toriel is the same in a Genocide Route and on a Neutral Route if the protagonist kills her when she offers mercy.

If the protagonist calls Toriel "mother," it surprises her, and she states that if it makes them happy, then she heartily approves of it.

Calling Toriel on her phone in the Ruins and flirting with her makes her assume the protagonist is joking, if they do it again she is unsure what to make of it. If they flirt with her after calling her "mother," she will become uncomfortable, and calls the protagonist an "interesting" child. She will also mention this in the epilogue.

If the game is reset, Toriel says that talking to the protagonist is like "meeting an old friend for the first time" and also says that she feels this way about most fallen humans.

Asgore
Asgore is Toriel's ex-husband. They were once extremely close, winning first place in the '98 Nose Nuzzle competition and were open about their affection for one another. During their marriage, Toriel's nicknames for Asgore included "Fluffybuns" and "Gorey."

Toriel left Asgore and New Home after he declared war on humanity. After they are reunited on a True Pacifist Route, Toriel criticizes his plan for freeing monsters but still believes that he deserves mercy, even though he is "terrible." When Asgore asks if they can be reconciled, Toriel declines.

Flowey
Toriel calls Flowey a "miserable creature" as she fireballs him to protect the protagonist. She is unaware that Flowey is Asriel.

Sans
Sans and Toriel do not meet in person until the end of a True Pacifist Route and the Family and Exiled Queen endings, where they both have become good friends. They started their friendship by telling jokes to each other through the door leading to the Ruins. One day, Toriel entrusted Sans with protecting any human that left the Ruins.

They continue to bond in the epilogue and text each other as Frisk backtracks through the Underground.

Trivia

 * Toriel's name is a play on the word "tu-torial," as she teaches the protagonist about how the game works.
 * Despite Toriel's motherly nature, she is not above swearing:
 * Toby Fox stated that it is possible for Toriel to have said the "F-word."
 * Toriel has a sock drawer despite never wearing socks in-game.
 * The protagonist's reaction to Toriel's sock drawer and Sans's sock pile is similar.
 * Toriel once wore a flower-patterned muu-muu; other monsters complimented her by saying "nice muu-muu," but she assumed everyone was calling her a cow and never wore it again.
 * If the protagonist bores the Dummy during their encounter, Toriel looks confused and moves to the next room without comment.
 * When attempting to name the fallen human "Toriel," the response is: "I think you should think of your own name, my child," and prevents the name from being used.
 * If Toriel was killed and the protagonist resets to the point before her battle, Toriel remarks that the protagonist looks like "they have seen a ghost."