I used to believe that two lizardmen lived under my bed and that they would grab me by the ankles to pull me under and kill me if I got my feet too near the bed while getting out to get water or use the bathroom. I got very good at leaping from my bed to the door and back again. Later, I adapted it so that the lizardmen were a bit more like Abbott & Costello and never managed to grab me-- I think I was trying to make it less scary for myself.
A childhood belief about monsters

others believed things like this
- I used to belive that zombie hands would burst trough the floor and grab my ankles.Anon
- When you saw a funeral go by, you had to grab a button on your shirt.Anon
- i used to believe if i was in a plane, i'd be able to reach out, grab part of a cloud and eat it— BOXXXY
- that bathroom tap water was recycled "potty" water from the toliet. — livingdeadgirl
- ***I used to believe that water towers was a place that someone lived and they controlled the water.— C H R I S T E N
- I used to believe that a morman was a scary person who lived underground(actually called a moleman).— Mike