What other pets should be avoided if you have a cat?

On the other hand, Pythons dumped out in Florida have been known to eat cats.

Cats can get along with a lot of animals. I think the secret is introducing them very carefully, or better yet introduce them as a kitten. With dogs and cats together, no matter what you do the cats always seem to end up in charge. The combinations I would be carefull of is cats with birds or fish. One of my cats knocked over a cage of two parakeets at a friends house. She heard the cage go crash and went to investigate. One of the birds was cowering in the cage and the other was attacking my cat. The cat was getting the worst of it, but then he was not the brightest cat in the world. This was the same cat who kept going around and around an octagonal fish tank, trying to get at the fish on the other side of the glass. Fish can be great entertainment for cats, but be sure the tank is securely covered so the cats don't go fishing.