Genius Cat
This one I had to be a little impressed with. The cat door is literal. It even has a doorknob on it, which is amazing. The fact that the cat can turn the doorknob is something truly spectacular. Since it was made so much like a real door, it is the only way the cat is going to be able to get through without help from the owner.
Even Stanley looks a little confused by it. The good news is that I’m sure that your landlord will never notice the doorknob sticking out of the bottom of the door. If they do, maybe they will be so impressed by Stanley’s ability to use it that they will overlook it.