 According to audio commentary on the Anchor Bays DVD, the scene in  the motel where the Stuff comes out of the mattress and pillows and  attacks the man on the wall and ceiling was shot in a room that  could turn upside down, allowing the Stuff to move up and down the  wall. It was exactly the same room used in  _Nightmare on Elm Street, A (1984)_ (qv) when Johnny Depp (qv)s  character Glen is sucked into his bed and his blood is regurgitated  back out onto the ceiling.