Since pets don't take bag or bank space, I'd agree with everyone else. Just let it sit unused in your list. You have 1000 slots, and even with all my trade fodder/doubles/extras, I'm still only at 675. You won't be wanting for anything except for withers later in the quest when you're looking for yet another pet to level.
<Kings and Queens> Alliance on Dawnbringer
-pet collecting OCD