The title sequence for ‘Alien’ was designed by Saul Bass, who was famed for creating opening credit sequences and posters for iconic films including ‘The Shining’ and ‘Vertigo.’ He was hired after Ridley Scott determined the film’s original poster idea — which had the title spelled in bones — was too gory.

John Hurt was not originally cast as Kane. The iconic character was initially supposed played by Jon Finch, famed for his Shakespearian work. He was replaced after he “he had to be carried off the set,” during production, per Scott. He was ultimately diagnosed with diabetes.

After years of debate, Alien conceptual artist Ron Cobb clarified what happened to The Pilot — or the “Space Jockey” — that appeared in the film without explanation. “A cataclysm caused the alien adults to die, leaving the eggs dormant in the chamber,” he said. “Years later, the Space Jockey race investigate the planet and are fascinated by this chamber. One of them gets face-hugged, the alien bursts from his chest, and goes on a killing rampage. The alien is shot and killed, and its acidic blood burns through the hull, leaving the Space Jockeys stranded on the planet. They sound out a distress call that, years later, the Nostromo picks up, by which point the Jockeys have starved to death.”

Several studios — Fox included — initially passed on the ‘Alien’ script. It only became a hot commodity after Walter Hill signed on as a producer and later, after the extremely successful release of ‘Star Wars.’

"Veronica Cartwright auditioned as Ripley in 1979 film Alien and arrived in England thinking that's who she would play. She learned otherwise when she was called in for wardrobe tests for Lambert."

In order to increase a feeling of claustrophobia among actors, Ridley Scott brought the walls slightly closer in during each day of filming without telling the actors.

“The fear you see from the actors in Alien for the chest burster scene was genuine. They didn't know that would be happening.”

“The guy who played the Xenomorph in ‘Alien’ was a 7’2” man from Nigeria named Bolanji Badejo. He was discovered by a member of Ridley Scott’s casting team by chance in a pub in Soho. His role as the Xenomorph was his only film credit ever.”

“The Alien in 'Alien' was inspired by a transparent deep sea parasite that eats other creatures from the inside out and then takes over their bodies to ride the seas in.”

“Sigourney Weaver actually made that ‘impossible’ basketball shot in Aliens: Resurrection.”

“Sigourney Weaver only earned $35,000 for Alien (1979) but got $1,000,000 and a share of the profits for Aliens (1986).”

“The saliva pouring from the aliens mouth in Alien (1979) is KY jelly, and the tendons in its jaws are shredded condoms.”

“Alien was based on a comedy film written by its screenwriter Dan O'Bannon called Dark Star, featuring an alien that was just a painted beach ball with rubber claws attached. He eventually started imagining what Dark Star would look like as a horror film.”

“The creators of the movie ‘Alien’ purposely littered p—s-shaped objects (including the alien itself) … throughout the movie.”

“James Cameron pitched the sequel to Alien by writing the title on a chalkboard, adding an ’s’, then turning it into a dollar sign spelling ‘Alien$’. The project was greenlit that day for $18 million.”

“H.R. Giger (the designer of the alien in Alien), once got stopped by Dutch customs because of his disturbing drawings, which they thought were photographs. Giger later said: ‘Where on Earth did they think I could have photographed my subjects? In h—l, perhaps?’”

“When Alien was first screened to audiences, ushers fainted, people vomited, and some ran screaming from the theater.”

“All the roles in 'Alien' were written as unisex, able to be portrayed as male or female. Ripley only became a woman when Weaver was cast.”

“H.R. Giger refused to give the xenomorphs from Alien eyes because ‘It's scarier if you don't know where they're looking.’”

“The eggs in Alien initially had a more v—l appearance complete with an ‘inner and outer v—a’. Producers worried that Catholic countries would ban the film, so Giger changed them so that ‘seen from above, they would form the cross that people in Catholic countries are so fond of looking at.’”