Character Analysis
Dad and Mom never actually appear in the story because it focuses on the kids; we don't get so much as a single illustration of them or one little line of dialogue. But they're still a big presence because while the kids get to pick out their new pet, they still have to operate under their parents' rules. They've been sent to the pet shop with very strict instructions that they can have just one pet:
NO…
Dad would be mad.
We can only have one.
If we do not choose,
we will end up with NONE. (25.1-5)
And it's not just the number of pets that they have to adhere to—the kids also have to pick quickly since their mother wants them to be home by noon. So even though the parents don't make an appearance in any scene of the book, they're still there in the background, waiting for the kids to choose a pet already and adding a bit of pressure to this already tense situation.