There is an bug with the pet from the Founders Pack. If you get more then the three different pets, because you have all 4 Founders Pack´s, you will have one pet style twice.
I think, that´s an issue. All different pets should only be shown once. Like you get a Mount twice, this will also shown only once in the Mount-Inventory.
Hope for a fix. Thats confusing me.
Here´s a screenshot: