(1) In Perl, bless is something sort of magical. New is just a function you create. So it could just be named "Defroobniculate". "new" is preferred of course, but whatever it does is essentially legal. Your packages technically don't have to return an object at all.

(2) Creating multiple blessed objects inside of new is perfectly legal, but I want to ask "why" here, as to why you are returning more than one. If you are constructing an object tree, for instance, usually you would expect the return of the root node. What you are doing is totally legal and valid, I'm just curious... I haven't needed a "new_dog_and_cat" function before -- though perhaps I could see a return of a list of objects (or a hash of objects) being useful. (I just want to find an example where that would be the case)