And then there is that lovely phrase "The catbird seat" which is nowhere better used than in James Thurber's story of the same name:
The wikipedia entry is also worth a read if you are curious (but remember, curiosity killed the cat... ;-)
Well, a few I can think of...
"Not enough room to swing a cat" hopefully that one's self explanatory.
"dead cat bounce" is a small, brief recovery in the price of a declining stock.
"cat that got the cream"
Interestingly in South Gloucestershire (my home Shire) there are a few Cat related place names... "Cattybrook Road" and the more worrying name "CatBrain Hill"; I'd hate to think if that hill was man (or cat) made.
“I shall sit down,' replied the cat, sitting down, 'but I shall enter an objection with regard to your last. My speeches in no way resemble verbal muck, as you have been pleased to put it in the presence of a lady, but rather a sequence of tightly packed syllogisms, the merit of which would be appreciated by such connoisseurs as Sextus Empiricus, Martianus Capella, and, for all I know, Aristotle himself.'
Your king is in check,' said Woland.
Very well, very well,' responded the cat, and he began studying the chessboard through his opera glasses.
And so, donna,' Woland addressed Margarita, 'I present to you my retinue. This one who is playing the fool is the cat Behemoth...”
? Mikhail Bulgakov, The Master and Margarita