Renaming the Trainer dressphere pets

I heard there was a way to do this, anyone know how?

Ask Barkeep in the Cabin, after obtaining the Dressphere, not that changing your pet name does anything. It might change certain attack names, but as far as that...

after obtaining the dressphere you say. Damn... That means ANOTHER new game plus -_-

Oh well... ty anyway

Rest in the Celsius' cabin once in each chapter. When you do it in chapter 5 you'll get a scene involving Brother and Barkeep. You can then talk to Barkeep and he'll offer to change the pets' names.