For the fifth time ever, best friends Elephant and Piggie have five BIGGIE adventures in one book! From award-winning, best-selling author and illustrator Mo Willems, this BIGGIE bind-up of Elephant & Piggie adventures will make readers want to celebrate! This bind-up includes the titles: I Am Invited to a Party! ; I Will Surprise My Friend! ; Happy Pig Day! ; Waiting Is Not Easy! ; and The Thank You Book .