The Kingdom of Fantasy book by Geronimo Stilton

I knew from the start that it was no ordinary day, but I certainly didn't expect to find a golden staircase in my attic. Up at the top, there was a door. And beyond the door was a world I never could have imagined -- the Kingdom of Fantasy! Along with my guide, a frog named Scribblehopper, I set off on an incredible adventure to save the Queen of the Fairies. But along the way, I had to face giant scorpions, witches, sea serpents, pixies, and dozens of other creatures that I had only ever heard stories about. Holey cheese, what a journey! Could I save the Queen . . . and my own tail?