Steven is the Roald Dahl Funny Prize shortlisted author of The Wrong Pong series and The Diary of Dennis The Menace series as well as The Nothing to See Here Hotel, shortlisted for the Sainsbury's Children's Book Awards.

He's also an actor, dancer and trained aerialist as well as a keen observer of trolls and their disgusting habits. His primary school headmaster was the fantastically funny author Jeremy Strong. Steven lives in London.

Jarvis lives in a very leafy and quiet part of Northern England with his girlfriend (who tells him what's good/bad and pretty much gives him most of his ideas) and their cat, who rips those ideas into tiny pieces.

He has always doodled wherever his career has taken him, from graphic design student to record sleeve designer to animation director. The way that he works always begins in a sketchbook with pencil.

From there it evolves into charcoal, photoshop brushes, pencil crayon or paint to finish the look. He uses many programmes, but the main ones are Photoshop, Illustrator and InDesign. Who Is Happy? is one of his first picture books.