After watching an episode of Goosebumps or something of the sort when I was younger, I was always afraid that a big bloody gross monster would come out of the drains or toilets and eat me.
A childhood belief about fear of

others believed things like this
- Atomatic toilets had people inside of them watching to see when you are done.Anon
- I used to be afraid of Tina Turner. I saw her as a monster or something like that.— Kinha SP
- I used to belief that mermaids lived in underground drains. Anon
- I thought the boogey monster was a monster that ate boogers at night in front of youAnon
- I Used To Believe The Monster Beverage/Energy Drink Was Monster Milk!— KellGirl
- i used to think boogers were chewing gum. Gross, i know!— ediop