In O'Bannon's script, the temple had an oxygen atmosphere. Cobb drew an octopuslike Face Hugger attacking a helmetless Kane.

 

An early autodoc. The whole apparatus containing the body would roll out on tracks to the seat in the foreground.

Cobb's early creature for the original script easily gave way to the monstrous Giger apparitions.

DAN O'BANNON: What really bothered me about the whole idea of this thing running around on the ship was why they did'nt just kill it. Why did'nt they spear the goddamn thing, or shoot it with some kind of gun that would'nt go right through it and penetrate the hull? Or why couldn't they get a bunch of long pointed shafts and drive it out the airlock? I mentioned that to Ron Cobb, and he said, 'Why not give it extremely corrosive blood that would eat through the hull?' And I said, 'Well, that doesn't make much sense; but it would certainly make it very, very difficult for them to deal with it on board the ship' - so I put it in.

I'm afraid Ron Cobb's ego was sorely wounded when he did'nt get to do the monster. He was endlessly frustrated because he could design aliens without number and they were all convincing and all unique and all startling to look at. But the problem was, he's a rationalist. I noticed this when we first started designing the picture. All these different things he was doing were coming out so well that I decided to have him have a crack at the derilict spaceship. But when I asked him to come up with an irrational shape he got very disturbed, He could'nt handle that. He kept coming up with convincing technology for a flying saucer or some other kind of UFO. And when it came to the alien, he had the same kind of problem. His designs weren't as bizarre, or as bubbling up from the subconscious, as the stuff Giger was doing. Cobb's monsters all looked like they could have come out of a zoo - Giger's looked like something out of a bad dream.

Ron Cobb standing in the autodoc as it nears completion.

The completed autodoc set, exactly as Cobb's concept.