Billy is trying to stay awake so the scary creatures of the dark won't come. But then he hears a squeaky little voice and notices some tiny purple footprints. Not only that, something has attacked his cheese sandwich. What could it be? Does Billy dare find out?

Billy hates swimming. It's cold and wet and horrible. And just when Billy thinks things can't get any worse, his pet mini monsters turn up at his swimming lesson and make one very big splash.

It's nearly Christmas and Billy and Ruby are feeling very excited. Billy has asked Santa to bring presents for his MiniMonsters and they're very excited too, until they try to help with the decorating and bring down the entire Christmas tree. Now the baubles are broken, the fairy is squashed and Billy's mother is feeling sad. Can the Mini Monsters make Christmas right again? And will Santa still come to them?

Billy is learning how to take care of the planet, and the Mini Monsters want to help to so they join the school trip to the recycling centre. But what will happen when Gloop falls into the recycling machine? Another laugh-out-loud Billy and the Mini Monsters story, with a strong underlying message about looking after the planet.

Billy's going to a sleepover party, at his best friend Ash's house. He's very excited but then everything starts to go wrong. Sam's feeling sick, Jack is scared and Ahmed has injured his foot. Will the sleepover be a total disaster, or can Billy and his Mini Monsters show that being with friends is what matters most of all?