Harry the poisonous centipede goes to sea - Lynne Reid Banks

Harry the Poisonous Centipede is now quite brave, but nothing can prepare him for this next adventure! He and best friend George are lost in a new and even scarier no-top world. Far from home, across the no-end puddle, they must negotiate a strange treeless cold desert, a Nest of Hoo-Mins, lots of noise-hurt and terrifying hairy-yowlers!

Harry woke up first. The straight-up-hard thing was jiggling. It was moving.
"What's happening?" asked George in alarm.
"I don't know. We're moving." Harry replied.
"Where are we? We're not where we were last night!" crackled George.
"I told you! This is a can't -get-out!"

Harry and George face the toughest adventure yet when they are shipped West in a crate of bananas. Far across the no-end puddle, miles away from home, they must find a way to survive the bitter cold and hide from the hundreds of Hoo-Mins do-diddling around them. They run away as fast as they can, but inadvertently squirm into a Hoo-Min Nest and come face to face with a hairy-yowler!

All Harry wants is to go home to his mother, and tell her how much he warm-hearts her before her time comes to "stop". But before they can even start the perilous journey home, they must escape the Nest and go out into the no-top world. Yet this particular Hoo-Min is fascinated by insects, and wants nothing more than to add some poisonous centipedes to his collection