Just as quick reminder — all “Alien” themed movies and whatnot, whether they like/admit it or not, derive from two 1939 stories by A. E. Van Vogt — “The Black Destroyer” (giant catlike monster plays dumb and harmless, is taken aboard spaceship, proceeds to start dining) and “Discord in Scarlet” (bizarre, shape-shifting organism plants carnivorous eggs inside space travelers). These were also Van Vogt’s first published stories and they are written with feverish intensity. The humans are no more than stick figures, but the aliens are unforgettable. Both included in the recommended book, Voyage of the Space Beagle.
(Of course it has to be admitted that the year before the Van Vogt stories, John W.Campbell published his masterpiece, “Who Goes There?” — which puts a carnivorous, shape-shifting alien into an isolated polar encampment.)