Dorothy and the wizard of oz

When an earthquake swallows Dorothy, her kitten Eureka and cousin Zeb, and Zeb's horse Jim, they're captured by the Mangaboos! The Wizard of Oz must save them by winning a magic contest - using only his wits and nine tiny piglets. Then: watch out for the savage Invisible Bears, who devour anyone they catch! Dorothy and her friends race across the Invisible Valley, trying to reach the spiral stairc...