The Wizard of Oz is a movie about a girl named Dorothy being sent to the land of Oz due to a tornado, where she meets the Tin Man, Cowardly Lion, and the Scarecrow. She goes on a journey along the yellow brick road to ask the titular Wizard if he could send her home back to Kansas, but is opposed by the Wicked Witch of the West.
Scooby-Doo and Scrappy-Doo (second series)
Scooby-Doo, Shaggy Rogers, and Scrappy-Doo were about to watch the movie in the Mystery Machine when Scooby accidentally tripped and fell unconscious. When he came round, the gang were swept away by a tornado and found themselves in Oz as the Scarecrow, Tin Man and Cowardly Lion. They meet the Yellow Brick Toad, who helped them until they ran into the Wicked Witch of the North by Southeast's flying monkey who took them to her castle. Scrappy melted her and they got a ride home from the Wizard of Oz's Whizoom, but it could only hold three at a time, causing Scooby to fall out and fall to the earth below. However, he woke up before making impact.
Scooby-Doo and the Witch's Ghost
Shaggy threw a bucket of water on the real ghost of Sarah Ravencroft, hoping it would melt her away as Dorothy did to the Wicked Witch of the West. However, it didn't work because of her being a ghost. 
What's New, Scooby-Doo?
A girl dressed as Dorothy, a guy dressed as the Tin Man, and another guy dressed as the Cowardly Lion went to the Halloween party held in Banning Junction Town Hall, where they mistook a scarecrow robot as their friend, Carl, who was supposed to meet them at the snack table.
Scooby-Doo! Pirates Ahoy!
- Scooby-Doo and Scrappy-Doo (second series)
- 111(c). Scooby's Trip to Ahz
- What's New, Scooby-Doo?
- 206. A Scooby-Doo Halloween (fancy dress people)
- DTV10. Scooby-Doo! Pirates Ahoy! (fancy dress people)