Answer:
My teeth are sharp, my back is straight, to cut things up it is my fate.
If you drop me I'm sure to crack. But give me a smile and I'll always smile back.
A hole leading in, a hole leading out, we connect to a cavern that is slimy all throughout. What are we?
What has thirteen hearts But no body or soul?
My first is an insect; my second is a border; my whole puts the face in a tuneful disorder.
you hold my tail while I fish for you