Do you mean something that allows crafting steak [​as example] into diamonds or diamond gear?

OR

something that swaps the visible textures of the items?

OR

something that changes drops? (cows drop gold and diamond vs leather and steak _or_ cooking chicken turns it into diamonds)?

I'm sure any of tese can be found if one were to look long enough, but finding someone who remembers one would be helped by knowing which is wanted…