Toriel

Toriel, as a boss monster, is very goat-like in many ways, having thick, white fur and small goat horns on her head. She is capable of using fire magic, able to control many a flame under her fingertips. She’s also quite overweight and chubby, her main outfit being a large, purple dress with a shield-like symbol known as the “delta rune” having three triangles at the bottom and a circle with wings.

Toriel takes care of The Ruins of the underground, an ancient, violet structure long since abandoned by the monster people. Eight humans fell before, the eighth, Frisk, freeing the monster people and allowing them to enter to The Surface again, the middle six, dying one way or another and being stored to break the bartier, and the first, Chara, being adopted by the Dreemurr family (even though she wanted to kill herself by falling into Mount Ebott in the first place) and after growing deathly ill, being carried to the surface again by Asriel, Toriel and Asgore Dreemurr’s son, absorbing her dying soul to pass through “The Barrier” and lay her corpse in a patch of golden flowers. The humans of the surface, believing He killed her, killed Asriel, who was later reborn as “Flowey” after his dust as absorbed by the flowers and given a bit of soul “determination”. The loss of their dear and only son brought devastation to the family, Asgore seeking vengence for the two children and beginning to collect human souls to break the barrier. This pained Toriel, as she didn’t wish to bring more death or war to monster kind. In the end they divorced, Toriel taking refuge in the ruins as Asgore, also quite broken-hearted, attempts to continue collecting souls through the help of the royal guard.