The Tale of the Valiant Ninja Frog, by Alastair Chisholm

Jamie and Abby are camping with Dad and they tell a bedtime story together. This story will star their favourites: a prince, a witch, a thief and some bears. "And the frog!" says Abby. This time there's a terrible ogre who's stolen all the keys to the kingdom. No one can get into their homes! No one can start their horses! It's a real mess. Our heroes must sneak into the ogre's castle and retrieve the keys. But when it comes to the crunch, only a tiny froggy hero, who's also a NINJA, can defeat the mighty ogre!