This book is called “The one and only Ivan” by Katherine Applegate. It tells about a gorilla named Ivan who once had been a wild one, now he’s in a mall where people stare at him all day.
His life was a peaceful one, until Ruby came, a young elephant who was in the wild once too. In an accident, Ivan promised a friend to help Ruby make her life better.
This story is amazing and life changing. I recommend it to everybody.