So, this might not be true, but a) It's funny and b) Costco really does have a great return policy. Anyway, according to this guy, he fell for an internet hoax called PenguinWarehouse.com, wherein someone set up a site pretending to offer pet penguins. Ok. Problem is, this guy bought a swimming pool for the penguin and installed it in his living room. Then, when he found out that the penguin site was a hoax, he returned the pool to Costco.

Manager: Sir, can you tell me why you'd like to return this pool?
Tynan : I was going to buy a penguin, but I was worried the pool was going to leak on my carpet. It doesn't say anywhere not to use it inside, but I don't think it's sturdy enough.
Manager: Are you being serious?
Tynan: Yes.
Manager: Ok... I guess we'll take it.
I provided my receipt and got my money back.

Um, way to go Costco? —MEGHANN MARCO

The Infamous Ghetto Indoor Pool [Better Than Your Boyfriend]
Penguin Warehouse [Snopes]