11 Most Terrifying Sci-Fi Movie Monsters

Though the Tremors series might have its tongue firmly in-cheek, that doesn't make the Graboids any less terrifying. Though the sequels have shown multiple iterations of the creatures in all shapes and sizes, the original are deathly simple - massive worm-like creatures that burrow underground and track prey by the vibrations they make when walking or running.

This, of course, means that all you have to do is just walk on the ground for one of these slithering behemoths to burst out of the ground and rip you to pieces. One victim dies not by their hands, but by dehydration after climbing up a telephone pole to escape them, but with no way of coming down without drawing them to him.

The very nature of these things means that almost nowhere is safe, and forces the characters to find alternative means of transportation that doesn't involve their feet touching the ground. One wrong move and the graboids will swarm you in seconds. The graboids aren't dumb animals either, capable of creating traps and diversions to better catch their prey.

Being indoors won't save you either, since the graboids will just attack a building's foundations or bore clean through a basement wall. Unless you're armed to the teeth and very very lucky, you don't stand a chance against just one of them.