Hattie Harmony: Worry Detective

Elizabeth Olsen View titles by Elizabeth Olsen

Robbie Arnett is the coauthor of the #1 New York Times bestelling Hattie Harmony picture book series with his wife, Elizabeth Olsen. He has toured the world as a professional musician and plays the guitar, drums, harmonica, and many other instruments that he's made from the items in his kitchen. He lives in Northern California, where he's always writing a new song.

Please visit him on Instagram @HattieHarmonyBooks.

Luciano Lozano is illustrator of Boys Dance!, Call Me Max, Our Italian Christmas Eve, and many other delightful books for children. His art is regularly seen in newspapers and magazines worldwide. While creating the art for this book, he listened to everything from classical music to bossa nova. He lives in Barcelona, where he's always drawing or dancing.

Please visit him at LucianoLozano.com and follow him on Instagram @Illustrista. View titles by Robbie Arnett

Originally from South Texas, MARISSA VALDEZ is a two times #1 New York Times bestselling children's book illustrator and author. She's a graduate of the Massachusetts College of Art and Design, where she received a B.F.A. in Animation. She loves to illustrate stories that are overflowing with humor, wit and totally out-there situations. In her spare time, Marissa gets her illustration inspiration by wandering around natural science museums, watching super-cool dinosaur documentaries and playing with her two fat cats in Birmingham, UK. View titles by Marissa Valdez