As a child, were you ever told a lie by a sibling or friend to terrify you?

As a child, my older cousin convinced me that the evil witch from Snow White could see me through the water in the toilet. The only way to disturb her visions was to flush, frequently. Me, being an impressionable five year old, believed him. My mother was convinced I had gone crazy, because I would go a little bit, flush, go a little bit, flush, and on. This lasted for weeks, until I finally told her about the witch in the toilet. She assumed a very serious expression and went about “banishing” the witch from the toilet.

Has anyone had a similar mean older kid who told them a joke like this?