There's no such thing as a natural-occuring ponzi. Something is a ponzi or it isn't. Neither gold and bitcoin are ponzis as there are no promised returns from (the) creators.

And same goes for dog coins. However, it is obvious enough that the creators do it for the profit. Even if they find alibis (that it has a usage), I can't unsee those as frauds. Still, they aren't ponzis. Ponzi has a really strict definition.