Housepets!

So, the going theories are: A.) The fourth puppy has been running around unsupervised and is causing all kinds of damage. B.) Bailey, King, or some cosmic entity are messing with Peanut by leaving clues all around the house. C.) There was a fourth puppy that has disappeared from reality, and only Pe...

Here's an idea for a twist: they could have had four pups, but the fourth was erased from time. Nobody would ever know that there was supposed to be a fourth one, but Peanut, being a former explorer of realities is the only one with the perspective to notice.