"The monster in Alien variously recalls the shark in Jaws (film), the demon in The Exorcist, the pods in Invasion of the Body Snatchers and even the benign extraterrestrials of Close Encounters. But the most terrifying adaptation is the mouth: as it grows in both size and ferocity, the infernal beast, conceived by Giger and realized by several visual effects designers, flashes not only jaws but jaws within jaws. After the first shocking, snarling show of teeth, all that's necessary to provoke our self-torment is the buildup of suspense, which Scott orchestrates with masterful visual and rhythmic command and the startling emergence of fragmentary features from some border or background of the image. Alien is scary enough to create a sensation and justify taking the "R" rating seriously, especially for young children. Yet, it is graphically restrained and subtly abstracted compared to the excesses of The Exorcist or Dawn of the Dead. There are two spectacular gruesome passages, but even here the horror concept is at least as frightening as the depiction. Scott has opted for the minimum effective gruesomeness, given the circumstances and current standards in trick-effect traumatization."