Kate Wilkinson started out as a children's writer for BBC Radio creating audio stories for pre-school listeners. She then became a radio producer for many years, working primarily on arts programmes, literary features and readings such as Radio 4's Book at Bedtime and Book of the Week. She completed the MA in Writing for Young People at Bath Spa University in 2018. Kate has two teenage boys and lives in North London with her partner who is a news journalist.

Joe Berger, the illustrator of Hubble Bubble, Granny Trouble and Superhero Dad, is a children's author, illustrator and cartoonist who also makes the occasional award-winning animated short film and title-sequence.

He is co-creator of the Berger & Wyse food cartoon in the Guardian magazine each Saturday, and has illustrated numerous books, inside and out, for children and grown-ups. Joe lives in Bristol with his wife, three daughters, two cats and a small dog.