The One and Only Ivan by Katherine Applegate

A gorilla named Ivan lives in a domain at the Exit 8 Big Top Mall and Video Arcade. Ivan’s best friend is an elephant named Stella. Ivan also has a friend named Bob, who is a stray dog who visits Ivan by sliding through a crack in his domain. Bob is not part of the mall. A new baby elephant, Ruby, arrives. Ivan tries to help Ruby get out of the mall because she isn’t happy at the mall. Mostly Ivan thinks about art and how he expresses himself. Ruby helps Ivan see his art through a different perspective.

--Mesha