This is the 'Cat Ark' (like Noah's Ark, but for a single cat) built by Youtuber prefabcat for his cat, Dinni. That looks like a pretty sweet pad. Plus if the whole world floods Dinni can just float on out to sea and survive for like maybe an extra hour or two until all the cardboard turns to mush. Personally, I wouldn't want to be the last cat alive on earth anyways. When the flood comes I'm going to climb out on my balcony and swan dive straight into a shark's mouth. When I reach the pearly gates Saint Peter will hold up a '10' sign before telling me my name's not on the list. I'll insist there must be some sort of mistake even though deep down I know -- I know.
Keep going for a stop-motion video.
Thanks to carey, who informed there was actually a fourth little pig you never hear about that built his home out of cardboard.