Soultale Frisk wears a blue hoodie and has brown with a little bit of orange hair. Her designs were made for them to look like a monster.
Soultale Frisk is sometimes shown to be in a pink and white bunny suit with the red Determination SOUL instead of a white SOUL. They have their eyes shut/closed like Undertale Frisk.
Toriel - Toriel is met after the Flowey battle and she guides the human around the Ruins like they were her child
Flowey - Frisk will get convinced that its Soul or Steal a soul during The Genocide Route
Pacifist - During the pacifist run, Frisk will fight Asriel and can leave the ruins with the monsters if they have the Determination soul when Asriel's defeat.
Genocide - During the Genocide run, Frisk's soul will turn pure black while fighting Sans.