Alien is a science fiction horror film directed by Ridley Scott, the first in the Alien series with a cast including Sigourney Weaver, Tom Skerritt, Veronica Cartwright, Harry Dean Stanton, John Hurt, Ian Holm and Yaphet Kotto. The film's title refers to an aggressive extraterrestrial creature called a Xenomorph attacking the crew of a spacecraft. Dan O'Bannon, drawing on previous science fiction and horror works, wrote the screenplay from a story he co-authored with Ronald Shusett. The film was produced by Gordon Carroll, David Giler and Walter Hill through their company Brandywine Productions and distributed by 20th Century Fox. Giler and Hill revised and supplemented the script; Shusett is the executive producer. The Alien and accompanying elements were designed by Swiss artist H. R. Giger, while concept artists Ron Cobb and Chris Foss designed the human aspects of the film.