“I am afraid of my visions.” Thus spoke H.R. Giger, the artist whose paintings led to him being engaged by director Ridley Scott to design the xenomorph for the first Alien film in the late 1970s.

That’s the tagline to pop culture’s favorite sci-fi horror movie — a film that pushed the genre forward with an incredible display of acting and top-notch production, with layers of themes and subtext ...