25 Things You Didn't Know About Alien
14. Attempts Were Made To Make The Alien Transparent
The filmmakers' original plan for the alien was for it to be transparent, or at least translucent if that was all they could manage. This would have reflected its status as an elusive creature, stalking its prey before they could possibly catch sight of it. Unfortunately, attempting to cook the molds was a disaster, and with the deadline looming the crew decided to give it a dark tone instead.
Coincidentally, the idea was a direct influence on the camouflage technology used by the titular monster from 1987's Predator, with which Alien is part of a shared universe.