The Hedgehog of Oz / Cory Leonardo.

Enhanced descriptions from Syndetics:

The Wizard of Oz meets The Wind in the Willows in this middle grade novel full of "old world charm and adventure" ( Kirkus Reviews ) in which a theater-dwelling, Oz-loving hedgehog goes on the journey of a lifetime to find his way home in this tale of loyalty, friendship, loss, and hope.

Marcel the hedgehog used to live with his beloved owner Dorothy, but since getting hopelessly lost, he's tried to forget the happy home he left behind. Now, Marcel lives a quiet life in the abandoned balcony of The Emerald City Theater where he subsists on dropped popcorn and the Saturday showings of The Wizard of Oz .

But when he's discovered, Marcel is taken far away from everything he knows and ends up lost once more. His quest to return to The Emerald City Theater leads him to Mousekinland, where he meets Scamp, a tiny mouse armed with enormous spirit (and a trusty sling-shooter). Before long, they're joined by an old gray squirrel, Ingot, who suffers from bad memories and a broken heart, and Tuffy, a baby raccoon lost and afraid in the forest. And the travelers attract the attention of an owl named Wickedwing, who stalks them as they search for the old theater.

From field to forest, glittering theater to the gutter, the animals' road home is a dark and winding journey. But sometimes you need to get a little lost before you can be found.