i used to believe that if you forgot or stopped believing in an imaginary friend they would turn into a monster and try to kill you.
A childhood belief about imaginary friends

others believed things like this
- I used to have an imaginary friend named Mr. Nobody. He would protect me from my imaginary enemy, Bad Elmer.— Kdees
- When I was little I believed that a night a monster will came and kill me.❤️🥺— @natalia_rd_
- I would turn the lights off and then leg it up the stairs thinking a monster would be chasing me.Anon
- My mum told me that if you picked your nose and flicked it on the floor then it would turn into a monster!— MadMack
- my aunt used to have an imaginary friend who instead of having blood had 7-up in her veins.Anon
- When I was about 6 or 7, I had an imaginary friend, who left for ice-cream one night. He never returned.— His name was Jimmy