Okay this is kinda two beleifs in one. When I was young, I used to watch "Tom and Jerry". My aunt had this cat and a hamster. I asked her where her hamster's tail was and she told me that he was being a bad little mouse and Santa Claus ran out of coal for him, so he put de-tailer in his chocolate. (I think she was making fun of me)So I took her cat and her hamster and put them in the same room, and was absolutely amazed when Tom caught Jerry. (the good thing was that my aunt caught Tom before he could eat Jerry, and I was punished)
A childhood belief about cats and dogs

others believed things like this
- When I was little I used to believe that comedian Jerry Lewis and rocker Jerry Lee Lewis were the same person.— Paul
- my parents were hippies and I use to beleive that Jerry Garcia was SAnta Clause. — Melissa
- I used to think that if you were the teacher's pet, you would turn into a hamster.Anon
- When I first heard of Amsterdam I thought it was "Hamster's Den"— Bootlebat
- For the longest time I believed New Hampshire was New Hamster and that was where all the hamsters came from. — Giny
- i used to set up traps to try and catch santa. i never caught him. — santa trap