Deadly Friend is a 1986 American science fiction horror film directed by Wes Craven, and starring Matthew Laborteaux, Kristy Swanson, Michael Sharrett, Anne Twomey, Richard Marcus, and Anne Ramsey. Its plot follows a teenage computer prodigy who implants a robot's processor into the brain of his teenage neighbor after she is pronounced brain dead; the experiment proves successful, but she swiftly begins a killing spree in their neighborhood. It is based on the 1985 novel Friend by Diana Henstell, which was adapted for the screen by Bruce Joel Rubin.