Belly Button Frog

There's a frog that lives in my belly button; he only comes out at night.
First time I heard a little croak, he gave me quite a fright.
I looked behind the cupboard and checked under the bed,
Then a little tickle made me peek beneath my shirt instead.

Every kid wants a pet, but to wake up and find a frog living in your
bellybutton ... Mum warned me to use soap.