I have been that if you don't clean your bellybutton it grows into a baby and you get a new one.
A childhood belief about belly buttons

others believed things like this
- When I was little I USED to THINK that hair grows by the ends.— Sirin
- When i was child i used to believe that if you tell lies your nose grows.Anon
- My brothers friend still thinks he will be a kangaroo when he grows up and he's 9!!!!!— Jane Rom
- If you touch your bellybutton, it will get infected.Anon
- That if you fiddled with your bellybutton it would unscrew your bum and it would fall off— Sundaeg1rl
- I thought liposuction was squeezing the fat out of your bellybutton. Too bad it's not that easy...— Angela