Her robe is black and blood red, and is frayed at the bottom. Her eyes are gaped, wide open and her irises are a bright red color compared to her counterpart, giving her a psychopathic look. Underfell Toriel has large fangs, and has red splotches pied along her fur. Whether it is just a discoloration or stained blood is unknown.
Toriel is seen to be similar as the original Toriel; motherly and caring. However, under the most minimal tension, she may become aggressive. She tries to keep the children for herself, always offering false love and care, but once they try to escape the ruins, she tortures them and often ends killing them.
Unlike the original Toriel, this Underfell version doesn't know how to cook well and ends up messing up her recipes. She uses demonic substitutions as ingredients such as blood, monster dust, etc. She asks Frisk a lot of questions in a psychopathic, confused and disarrayed way. Instead of Cinnamon Butterscotch Pie or Snail Pie, Toriel makes Crab Pie.
Frisk - Toriel cares for Frisk while they are in the Ruins, but she tortures Frisk when they try to leave.
Asgore - She is the ex-wife of Asgore.
Flowey/Asriel: Flowey/Asriel is Toriel's and Asgore's son. Toriel hates Flowey though because of his kindness.
Chara: Chara was the adopted child of Toriel and Asgore who died from a bee overdose.