We are unsure if Rat is a full person, or a mirror fragment. She says she is Mouse's twin although she is a year older. Because of Mouse's playful adventurous spirit she would often get into situations that would anger the family and it was always Rat that stepped forward for the punishment. She is extremely protective of Mouse and will still take her place if she deems it necessary or if she feels Mouse might be in danger. She states as long as Mouse is alive she must remain to protect her.
Rat has a rough dirty appearance to her. Her hair is slightly darker and a lot longer than Mouse's but it is obvious they are related. Her skin is smeared with dirt and her bare feet are usually caked in mud. She has a strong defiant personality and is very willful.