Return to Oz (1985)

It has been six months since Dorothy has returned home from Oz and she still cannot sleep. She has been going on about imaginary places and people so much that Aunt Em takes her to see a doctor. She promptly escapes from the mental hospital and wakes up in Oz where her pet chicken, Billina, can now talk. There she meets a whole new bunch of friends and they set off to rescue the Scarecrow from the evil Nome King who has found her ruby slippers and used them to lay waste to the Emerald City and take over Oz.