Suddenly I don't feel so guilty stepping on ants. note
- The killer ants that eat people alive. Oh yes, and they're coordinated enough to form a tower to reach you if you're out of reach.
- Know what's scarier? There are really insects like that in South America. This was NOT science fiction.
- A woman being disintegrated. Even more so in the adult novelization. As the alien beings leave this world, Spalko actually feels her skull painfully transform into quartz as the aliens flood her mental consciousness with all the knowledge in existence. It gets worse, and just before she dies Spalko gets a terrifying glimpse at the Eldritch Abominations.
- A suburban neighborhood populated by eerily smiling plastic dummies, complete with "Howdy Doody" playing on a TV set. The creepiness isn't reduced by the fact that it's a nuclear bomb test site.
- Irina Spalko's plan for the Crystal Skull, i.e. using its power to brainwash large numbers of people into mindless followers of communism is downright terrifying, and the psychological nature of this attack is what makes it so bad.
- The Greys have always been creepy but to have one looking super pissed like the resurrected alien was at Spalko at the end? Terrifying.