By Mo Willems, Author & Illustrator. Gerald is careful. Piggie is not. Piggie cannot help smiling. Gerald can. Gerald worries so that Piggie does not have to. Gerald and Piggie are best friends. In A Big Guy Took My Ball! Piggie is devastated when a big guy takes her ball! Gerald is big, too…but is he big enough to help his best friend? For ages 3 and up.