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 vacation time for Billy and his Mini Monsters. They’re off on a plane to Spain. There are just two small problems – Peep’s been seen by airport security and Trumpet and Gloop have gotten LOST with the luggage. Can Billy get his Mini Monsters back in time for take-off?

Billy’s off to a birthday party. He can’t wait! And neither can his Mini Monsters… they’ve snuck into the party too! Soon Gloop’s in the gelatin, Trumpet’s on a balloon, and Fang-Face is about to become the birthday surprise…

Billy’s moving house and everything is changing – new bedroom, new neighbors, new school. At least he’s got his Mini Monsters with him… or so he thinks. The Mini Monsters have gotten LOST in the move. How will they ever find their way back to Billy?

Billy is feeling nervous about his FIRST EVER school trip, so the Mini Monsters decide to come along too. They promise not to be any trouble…but who’s causing a commotion in the creepy-crawly cages? Why does the T. rex skeleton keep moving? And Billy can't help wondering about the really tiny Egyptian mummies… Can he save the trip from disaster?

Billy and his family are off to the beach. The Mini Monsters are very excited to be going too. Soon they’re building sandcastles and enjoying their picnic. It’s all going so well… until Trumpet is stolen by a seagull! How is Billy EVER going to get him back?

When Billy arrives at the Halloween party he finds Sparkle Boogey in the apple bobbing, Trumpet in a pumpkin, and Gloop playing Guess the Body Part. Can Billy save Halloween?