“O’Bannon introduced Scott to the artwork of H. R. Giger; both of them felt that his painting Necronom IV was the type of representation they wanted for the film’s antagonist and began asking the studio to hire him as a designer. 20th Century Fox initially believed Giger’s work was too ghastly for audiences, but the Brandywine team were persistent and eventually won out. According to Gordon Carroll: “The first second that Ridley saw Giger’s work, he knew that the biggest single design problem, maybe the biggest problem in the film, had been solved.” Scott flew to Zürich to meet Giger and recruited him to work on all aspects of the Alien and its environment including the surface of the planetoid, the derelict spacecraft, and all four forms of the Alien from the egg to the adult”
Paul Greer 