The grey cat (also known as Cat #1, Mirci #2 or #CCCCCCat) is the Éminence grise among the constant inhabitants, and not just because of her color. She does not care about what she is called (although even she admits that Cat #1 is way cooler than the other names). In fact, on a regular day, you won't even see her, but rest assured, she is the one pulling the strings behind the scenes. Her only goal is world domination. Well, of course, when it comes to food, she can put away the scheming and formulating evil plans. Actually, she does it quite quickly.
If you meet her, and it is not feeding time, then probably her evil plan came to its next phase.