Asgore is the King of the underground he is the husband of Toriel and the father Of Asriel he is a good King and kind he is trying to protect every monster of the underground you are Frisk

Toriel is the queen of the underground she is the wife of King Asgore she is kind and loving she shaved you before you got killed by Flowey you are Frisk

Papyrus is a skeleton he has a brother named Sans papyrus dream is to be in the royal guard he is trying to capture you so he can be in the royal guard you are Frisk

Sans is a skeleton and he has a brother named papyrus Sans loves to make jokes and pranks he is lazy and he loves to eat and drink ketchup you are Frisk

chara is the first fallen human I think they are the sibling of Asriel sometimes they are evil sometimes they are nice and you are Frisk