Alien: early Alien beast drawing attributed to Dan O'Bannon

leading from

 HR Giger's Passage Temple (Life)

and

Alien Explorations: Alien: The biomechanoid that O'Bannon wanted ? 

and 

  HR Giger's Necronom IX

O'Bannon sketch, Rocket Blast Comicollector 148

O'Bannon's sketch, Phobos #1, Summer 1977

a) Dan adapts ideas from Necronom IX
It is complicated to point out exactly what Dan had done but he had adapted certain details for his own alien drawing. Should there be more of the drawing that might help to put the image into perspective, and perhaps a detailed scan might help to show more?

He took the eye like forms, transformed the shadow behind the ears into a sort of a collar. 

The exposed bones of the arm for hand holding the ribbed phallus transformed into pincers and the tip of one of the bulbous forms in the lower half of the picture has become the joint to which what looks like a pincer connects. 

The upper ridge of the open nasal cavity to the far left becomes a raised spike sticking out from where the nose of the creature might be if it had one. 

The ribbing of the phallic form inspired the ribbing of the front of the neck. 

The ears became the exposed almost decomposing areas on the back of the skull just as the place where the insect limb sticking out of the Necronom's head has as well. 

The insect limb suddenly transforms into the tusks of O'Bannon's creature, while the mandibles below the eye like forms become the side mandibles of O'Bannon's creature. 

The general shape of the cranium however seems to drift towards the general peanut life form of the one in the head of Necronom i (1976)

Comparison images between Necronom IX and O'Bannon's alien sketch.

1. Yellow represents the head features.
2. Pink colour represents the tusks,  pincer.
 3. Blue represents the ribbing and its development with the curvature of the head,
and also the peanut shape of the head

See above for key to outline colour

See above for key to outline colour 

b.) Early Alien Beast drawing released with "Memory -The Origins of Alien"documentary

(b.i) Design also references a limbless character from HR Giger's Passage Life Temple (1974).
As soon as the alien beast was viewable as a whole drawing on page with the release of the documentary "Memory -The Origins of Alien" , there were more possibilities  and on 31st of Jnauary 2019 I had another idea.

Source: https://gritdaily.com/alien-origins-memory-sundance-40th-anniversary/

b.ii) A Biomechanoid character as seen in the painting. He is to be found on the left  side of the actual painting

Passage Temple Life (1974) With the biomechanoid entity perched on the left.

b.iii) The biomechanoid character reversed next to the early Alien beast
The alien beast design borrows the collar, the blank eye, the bald cranium. The leg of the woman behind him turns into its hand, while the hand of the woman behind him turns into a leg