Jennifer E. Smith is the author of The Creature of Habit, illustrated by the award-winning Leo Espinosa, and nine novels for young adults, including The Statistical Probability of Love at First Sight, Windfall, and Field Notes on Love. She earned a master's degree in creative writing from the University of St. Andrews in Scotland, and her work has been translated into thirty-three languages. She lives in Los Angeles.

Leo Espinosa is a New York Times bestselling illustrator and designer from Bogotá, Colombia. His picture books include The Creature of Habit by Jennifer E. Smith, No More Naps and NO is All I Know! by Chris Grabenstein, Islandborn by Junot Diaz, for which he was awarded a Pura Belpre illustrator award, and The New York Times bestseller The World Belonged to Us by Jacqueline Woodson. Leo's award-winning illustrations have been recognized by American Illustration, Communication Arts, Pictoplasma, 3x3, and the Society of Illustrators. In addition, he has given multiple lectures and workshops at schools and institutions such as Parsons School of Design and Pratt Institute as well as serving on the faculty of the Rhode Island School of Design.