Hugh Crain is the main antagonist of the The Haunting of Hill House, its film, and the subsequent remake.
Crain was the owner of Hill House, the titular haunted house, and is the main source of the hauntings there. Crain is unseen in the book, and in the original film, but his backstory is given and is implied to be the cause of all the mysterious supernatural events there. Crain is given a far bigger role in the remake, as being the sole ghost that lives there, eager to drive anyone insane, and possesses and attacks objects and people. In the original, Crain never murdered any children, he was just an arrogant bully and womanizer. However, in the remake he is shown to have brutally murdered several innocent children from his mills. Their ghosts are also the main hauntings, but unlike Crain, they are friendly and want to tell the humans about their pasts. Crain is defeated in the climax of the remake where he actually appears as a smoky demon.
Hugh Crain is shown as a tragic villain and somewhat of a womanizer. He had several affairs; his first wife died when she set foot on the House's grounds.
His second wife died when she was returning home and her carriage hit a tree. Hugh was devastated by this and he became a recluse. It is implied his ghost is the main one who haunts the House.
Hugh Crain's story is given as a reason why the Hill House is haunted. Crain married several times and was unsuccessful, all his wives died. Crain is implied to have been Eleanor's grandfather, and is driving her mad with visions of the past. Hugh is implied to have been the ghost responsible for Eleanor's death.
The Haunting (1999 Remake)
This characterization of Crain is far more evil than any of the two previous installments, who were both portrayed in a tragic light, whereas he is just a downright monster in the remake, both inside and out.
Wanting to have children, but unable to do so, Crain kidnapped children from his cotton mills and slaughtered them, then burned their own bodies in the fireplace, trapping their spirits and forcing them to remain with him, providing him with an 'eternal family'. Crain had a second wife named Carolyn, from whom his granddaughter, Eleanore, is descended. He was able to cover up their deaths with records by merely claiming they died of illness or factory injuries. At some point, he drove his first wife to suicide and later murdered his second one simply because she knew too much. Once his house is accompanied by Eleanore and a few other visitors, he begins haunting them. Towards the end of the film, he seals up the house, trapping them all inside. A frustrated Luke defaces a portrait of Hugh Crain. Crain's enraged spirit drags Luke to the fireplace where he is decapitated. Nell is able to lead Crain's spirit towards an iron door. The spirits pull Crain into the door, dragging him down to Hell. Nell is pulled with him, inflicting fatal trauma on her body, but the ghosts gently release her on the ground. Her soul rises up to Heaven, accompanied by the ghosts.