Demons

The Ghosts of the Collingwood Psychiatric Hospital are instances of supernatural phenomena that occur within the abandoned Collingwood Psychiatric Hospital throughout the movies: Grave Encounters and Grave Encounters 2.

Appearance and behavior

The Living Patients make their appearances in different forms throughout the Grave Encounters duology. Unlike other poltergeists that manifest throughout the films, instances of Living Patients are ghostly entities that assume corporeal forms, appearing in the flesh as former mental patients and hospital staff, characterized typically by their emaciated appearances.

Grave Encounters (1)

1. A girl whose face is recognizable as human, but appears bruised; as the investigation team approaches the girl, she turns in their direction and screams, her face contorting into a ghostly visage.

2. A girl emerges from a blood-filled bathtub and pulls in one of the members of the paranormal investigation team. He disappears along with the apparition, having apparently ceased to exist in the physical world.

3. A male patient whose tongue had been severed by unknown means appears to Lance Preston; the patient is clinging onto the wall, blood pouring from it's mouth. It proceeds to chase him throughout the hospital.

4. A corporeal image of Dr. Arthur Friedkin and two nurses in the midst of conducting a lobotomy on a patient in an operating room. Dr. Friedkin appears before Lance Preston and confines him to an operating table before lobotomizing him. They appear to be tall, pale-skinned humanoid creatures that haunt together the Collingwood hospital in the night along with ghosts. They might even be undead patients and residents of the hospital.

Grave Encounters (2)

In the second film, a group of film students led by Alex Wright are led to the Collingwood Psychiatric Hospital by an anonymous entity known as "Death Awaits". Subsequently they find and manage to break into the building in which they planned to film a documentary/horror film based on it's predecessor. During their exploration they encountered the following:

1. A young girl - self addressed as Kaitlin - whose face contorts into a twisted version of herself, prompting the film team into a hasty retreat.
2. A tall, emaciated figure towering at a height of 7-8 feet; it's jaw is grossly extended, as though it had been violently unhinged.
3. A female child appears in a ventilation shaft situated in the underground sector of the hospital; her limbs appear bent at odd angles.

Backstory

It is implied that instances of Living Patients in the Collingwood Psychiatric Hospital are one of many consequences of the occult activities partaken by Dr. Arthur Friedkin throughout his time as the institution's head physician.

Before his death at the hands of a patient, a prior satanic ritual resulted in the opening of a portal between the world of the living and the spirit world, effectively dissolving the boundaries between the two. Consequently, Dr. Friedkin, his patients, and members of the medical staff became spiritually bound to the building, rendered incapable of escaping.

Over time, the Collingwood Psychiatric Hospital itself became unaffected by physical and geometrical laws present in the world of the living.