Answer:
An image taken from real life
Sitting down you have it, Standing up you don't.
Kids play it and Michelangelo sculpted with it.
A red house is made out of red bricks. A blue house is made out of blue bricks. What is a green house made out of?
The little pink nub that helps rectify mistakes.
Though not a plant, has leaves. Though not a beast, has spine. Though many wouldn't need this thing, It's more valuable than wine.