[original concept, design and illustration by Dan Green] original concept, design and illustration by Dan Green original concept and illustrations by M.P. Robertson original idea and illustrations by Jean Jullien rational graphic design and illustration / [original concept] by Roger Hargreaves ; written and illustrated by Adam Hargreaves. designed and illustrated by Dan Green. original concept by Roger Hargreaves ; written and illustrated by Adam Hargreaves. [concept and illustrations by Colin Petty].