Then decide on games. I had planned a mouse scavenger hunt with catnip mice, found in bulk on eBay. I found a word search (Googled "warrior cat word search") for some down time when things got crazy.
I had a craft table set up so the kids could make headbands with cat ears and tails. Dollar store headbands and ribbon for tails, scrapbook paper for creative license, and they did their own thing.
In the terminology of Warrior Cats, the term "dirt" refers to "poo", so I got a litter box, cleaned it out, filled it with puffed rice and tootsie rolls, and the girls had to blindfolded reach in for "dirt".
We also had a cat lapping water contest...well, not really technically a contest, because there wasn't a prize, but they liked it so much they did it twice! It was pretty darn funny to watch.
Now, about the food. I had a dear friend save me her cat food cans, and she cleaned them out and I lined them with cupcake liners, and they served as wonderful little snack bowls for such feline fare as goldfish, Swedish fish, and then we had to have Peeps marshmallow chicks. Our "fresh kill" was fruit (I know, not cat food, but I needed something healthy, right?) and chicken nuggets. Just happened to have mason jars (don't ask why!), so I adorned them with twine for refills if the kiddos wanted it.
They also drew paw prints with chalk leading up to the house. We had goody bags ready for each guest, and had some personalized stickers made at Oriental trading company for the party. And yes, I know, that is a zebra striped bag...but when you Google cat paper goods, all you get is "Cat in the Hat." I tried.
Everyone was given the code of the "Clan".
The cake was, well, a cake, and the girls drew the design and gave it to the decorator at the bakery. No homemade cake this time...I was "dirt" tired!
All in all, a great time, and if any of these ideas help someone not have to recreate the wheel, that would make me very happy!