Answer:
Only two backbones and thousands of ribs.
What comes once in a minute, twice in a moment, but never in a thousand years?
The itsy bitsy teeny weeny yellow polka dot variety is quite popular.
Mobsters judge the quality of a vehicle by the size of this
Sleeping during the day, I hide away. Watchful through the night, I open at dawn's light. But only for the briefest time, do I shine. And then I hide away. And sleep through the day.
You use it between your head and your toes, the more it works the thinner it grows.
Difficult
Animal
Easy
Food
Funny
Kids
Logic
What am I?