* Creator/StephenKing, of all people, wrote about the 1978 version that he found some of the effects so disgusting he was surprised it was released in theaters without an R-rating.
* The 1978 version's ending. Brrrrrrrrrrrrrr. [[spoiler: Matthew returns to his pod-controlled office and blends in, whilst background events make it clear that he only slowed down their efforts to grow the pods and ship them out to the rest of the world. He takes a walk and is greeted by Nancy... then, as the page image shows, he points at her and pulls a NightmareFace as he lets out a pod-man's distinctive howl.]]
* Whenever a duplicate is "born" from the same version.
* The concept, the film-specific execution, and the ''[[spoiler:[[MixAndMatchCritters fucking dog with its owner's head]]]]''
* In the original film, Miles kissing his girlfriend, [[spoiler: and she's one of THEM.]]
* There's a particularly chilling event in the background towards the end of the 1978 remake - we see a group of (unconverted) children on a field trip being taken into a building. You can hear one of them complaining about how they don't want nap time already.
* Late in the 1978 version, where [[spoiler:the original version of Elizabeth disintegrates in Matthew's arms, and the duplicate version appears nearby]]. The 1993 version has similar effects for most of the main victims, and while they don't quite have the creep-out factor of the preceding version, they're still pretty discomforting to watch.
* Need we mention the trailer and its final line?