About Derek Walter Books by Derek Walter The True Adventures of Esther the Wonder Pig by (author) Steve Jenkins, Derek Walter & Caprice Crane illustrated by Cori Doerrfeld Ages 4 to 8 Grades p to 3 The True Adventures of Esther the Wonder Pig by (author) Steve Jenkins, Derek Walter & Caprice Crane illustrated by Cori Doerrfeld Ages 4 to 8 Grades p to 3