a) References cartoon from "Plop!" magazine?
" Plop!#1 (Published October 1973), published a cartoon by a cartoonish by an artist with the name "Moir", and it seemed to present the basis of the outsized alien pilot drawn by Moebius
b) The figure on the operating table and the the outsized pilot/ space jockey by Moebius.
c) Legs with hands replacing the feet become the space jockey's arms and hands
d) he rounded chemical flasks become the three explorers
e) The upper torso of the Frankenstein's monster type humanoid becomes the upper part of the space jockey, his back rest and mechanical support with device over the head