Toni Buzzeo s first two books in the series, Whose Tools? and Whose Truck?, have sold more than fifty thousand copies. Toni is the author of the 2013 Caldecott Honor Book and New York Times bestseller One Cool Friend, as well as many other books for children.

A former elementary school librarian and secondary teacher, she now presents at schools, national and international library and reading conferences, and in district and regional staff development trainings. Buzzeo lives with her husband in Arlington, Massachusetts.

Diana Sudyka is a Chicago-based illustrator who got her start designing and screen-printing posters for musicians such as St. Vincent, Andrew Bird, and the Decemberists.

She also volunteers at the Field Museum in Chicago, where Sue the T. rex is housed.