Adam Guillain is a children's writer, musician and a co-founder of Storytelling Schools. Charlotte Guillain taught English to air traffic controllers and nurses before deciding a career in publishing would endanger fewer lives. Since meeting in Zanzibar while working with Voluntary Services Overseas, they have written several picture books together including Supermarket Gremlins, School for Dads and the George's Amazing Adventures series. In celebration of books and reading for everyone, the authors happily donate 10% of their royalties for World Book Day Monster to World Book Day charity.

Ada Grey studied illustration and later took a role in design. Moving back into illustration, Ada set about designing her own unique picture book style, characterised by an energetic palate, adorable, lively characters and a delicate use of texture. Her books include Shhh! Don't Wake the Royal Baby, School for Dads, Poo in the Zoo and Hippobottymus. She has illustrated several books for Bloomsbury, Little Tiger, Egmont and Macmillan. Ada lives by the sea in Brighton with her daughter and ginger tom, Tiger.