Volsunga Saga
The Volsunga Saga—sounds fancy, right? This 13th-century epic based on older Norse mythology describes the origins and eventual downfall of the Volsung clan. More particularly, it tells the story of Fafnir, a dwarf who was transformed into a dragon by his greed. Oops.
Instead of a wish, the Volsunga Saga relies on a curse to demonstrate the danger of greed. Also, spoiler alert: where Midas gets away with just a bath, Fafnir gets killed in the end. Oh, and they cut his heart out. Brutal.
Want to read the whole story? Check it out.
P.S. There are tons of other cultural myths about the dangers of greed. Try searching around yourself and see what you can find.