Unlike Polymorphism, the concept of 'Save Dog as Virtual Chicken' is "Transformative" -- like the 80's T.v. show Manimal, and maybe that 90's movie with Rob Schneider (The Animal?).

Save Dog as Virtual Chicken involves transmogrification, which must occur deep inside the Dog, and requires the dog to be aware of the inner workings of chicken. (or alternaitvely a dog-chicken translation-entity must be aware of how both dogs and chickens work, and have access to the innards of the dog.

So what are some other ways this concept can be used?

Lists in sharepoint expose a '.toDataTable' method. That's one example. The 'toString' method. That's transformative. Serialization is transformative, (e.g. Turn Customer object into a chunk of text). Import/Export routines that move data from one application to another, are often transformative. Do the words 'bridge pattern' fit in here?

Back to basics. Save email as ToDoList. Save email as bug. save spreadsheet as application. Save spreadsheet as virtual database. Open database table as excel pivot table. Magic! Convert dog to virtual chicken!