When I was little and my parents were together, they let me watch the miniseries adaptation of King's It. That night, I couldn't look at the toy clown hanging on a swing from my bedroom ceiling the same way. My brother managed to convince me it was real, so I started screaming. My dad came in, ripped it from the ceiling, and threw it against the wall, saying, "There's your damn clown!" It took me a while to get used to clowns again.
I also remember seeing the 80s The Fly and imagining seeing the main character crawling on the ceiling. The movie is both disgusting and horrifying, and it left a strong impression on me.
I remember seeing the Twilight Zone episode, "The Dummy," at a young age as well. It wasn't violent, but I had an extreme phobia of ventriloquist dummies at the time, and it haunted me for years.