20 Things You Didn't Know About The Xenomorph
18. Anatomy Of An Alien
The original Xenomorph costume, as worn by Nigerian actor Bolaji Badejo, contained a casting from a real human skull, to give the creature that authentic humanoid appearance.
The rest of the face was finished off with a rather disgusting KY jelly coating, which acted as drool and recycled condoms which when shredded looked rather like tendons inside the creature's mouth.