While Jurassic Park's T-rex may not necessarily be "creepy," being one of cinema's scariest creatures (and one that actually existed!) means it deserves an honorable mention on this list. Steven Spielberg's prehistoric box-office smash-hit scared countless viewers. With amazingly realistic animatronic creations, Stan Winston and his studio brought the animals to terrifying real-life. Even more terrifying is that, on occasion, the T-rex would come to life on its own, scaring the crew. In scenes where the mechanical beast would come into contact with water, the water would affect the internal connections causing them to malfunction.