Old Woman

The Old Woman, whose real name is revealed to be Parker Crane, is the spirit of an serial killer residing in the Further. Like with all spirits inhabiting the Further, her identity was unknown, but her intentions are more malevolent than the others. He was the secondary antagonist of Insidious and the main antagonist of Insidious Chapter 2.

Insidious
During the opening scene, the old woman is seen outside the window holding a candle. Later, when Lorraine visits Josh, Renai and Elise and tells Josh about the old woman. She recounts that Josh used to suffer night terrors as a child due to an 'old woman' visiting him at night. Dismissing his fears as superstition, as well as telling Josh to grow up and shrug away the bizarre dreams, Lorraine became aware of the malevolent hag's existence when she witnessed her presence in photos with Josh in them. Disturbingly, in a chronological span, the Old Woman seemingly moves in closer to Josh as he ages, nearly touching him in one photo.

Elise explains that the Old Woman is a 'parasite' who befriended Josh's astral form in an attempt to possess his physical body. The only way to stop her from doing so was to repress Josh's memory of her and cease taking photos of him. However, Josh developed a subconscious fear of having his photo taken.

Towards the end of the film, the Old Woman reappears to Josh by standing outside a window. Josh, filled with anger and fear, lashes out at her, shouting "LEAVE ME ALONE!!". She seemingly retreats back into the darkness while Josh and Dalton escape the Further together.

The Lambert family celebrates that the nightmare is over, but Elise feels something wrong. Taking a quick picture of Josh, Elise sees, much to her horror, that his image is replaced by the Old Woman. In retaliation, the Old Woman strangles Elise with Josh's body and the movie ends with seemingly leaving the fate of Josh ambiguous.

The films ends with the Old Woman blowing out the candle into complete darkness.

Insidious Chapter 2
In Chapter 2 the old woman is shown to actually be a serial killer (Parker Crane) who was abused by his mother. He dressed as a old woman in  a wedding dress to hide his identity. His mother raised him as a little girl causing him self to have a complex. He was hospitalized after a self castration and then killed him self by jumping from a great high. After a encounter with a young Josh. He was seen then after by Lorraine as a ghost. It was said he targeted Josh because he envied his youth. At the ending of Chapter 1 he took over Josh's body and killed Elise. He was arrested and later released via lack of evidence. The Parker soul was deteriorating Josh's body due to him being physically dead. He was then convinced by his mother's memory that he needed to kill Josh's family to save the body.

Appearance
The Old Woman wears a black Victorian dress, laced with black finery, and holds a small, red candle in her hand. Her appearance is ghastly, as she sports long, unkept hair, dark eyes and a face laden with wrinkles and pockmarks. This is later shown to be a disguise as a serial killer.