Answer:
You fill it and it empties, A metaphor for plenty, Depending on what half you see, It's either full or empty
It's tough as nails, Or soft as snow. People use it for their rink, Some just put in their drink.
What is broken if you say its name?
Tear one off and scratch my head, what once was red is black instead!
He died for people's entertainment.
People take me on walks and I run and have fun. What am I?