She was the terrorizing murderous ghost plaguing the small town of Toledo, Ohio and the murderer of Toledo Denizens Steven Shoemaker and Toledo High School student Jillian.
Mary was a 19-year-old girl living by herself in Fort Wayne, Indiana. She had won a few local beauty contests and dreamed of getting out of Indiana, and becoming an actress. She was murdered on March 29th (year unspecified) when someone broke into her apartment and murdered her, cutting out her eyes with a knife. Before she died, in front of a mirror, she tried to spell out her killer's name but only managed the letters T-R-E.
A surgeon called Trevor Sampson was suspected but nothing was ever proved and her murder went unsolved. In revenge, Mary haunts the old mirror, killing people hiding secrets about unsolved deaths. She was destroyed by Dean and Sam after she escaped from her mirror and they showed her her own reflection - causing her to kill herself because of all the deaths she had caused.
- Biokinesis - Able to make her victims eyes bleed, and caused them to accumulate a lot of blood within the brain, she used this to kill them. This could be used upon her by showing her her own reflection while she was using the power on a victim. The power would then destroy her.
- Possession - She possessed mirrors, and also could possess people reflections, but not them.
- Teleportation - She could travel from mirror to mirror.
- Super speed - Out of the mirror, she could move unimaginably fast.
- Mind Reading - Due to being in a mirror, which as the lore said could reveal the secrets of a person, she knew if a person was or at least thought they were responsible for a death.