As he inspects one, a creature springs out of it and attaches itself to his face.
Tom Skerritt, Sigourney Weaver, Veronica Cartwright, Harry Dean Stanton, John Hurt, Ian Holm in Yaphet Kotto igrajo člane posadke tovorne vesoljske ladje, ki na samotnem planetu naletijo na smrtonosno naslovno bitje ter so prisiljeni v boj za preživetje.