Among the many things I hate, here are the two major ones:
dogs, and that despicable orange cat.

That Despicable Orange Cat
When I was still in the pet store at the mall, an orange kitten there wouldn't let me get near the food. This is one of the few things my future humans saw. I got up on top of the litter box (it was covered) and jumped on that cat.  Served it right. Well... this is a new orange cat. The despicable orange cat always trespasses onto my property! That cat has some nerve. I've fought it before. And sometimes I've gotten hurt pretty badly; but I always get better. Usually one of my humans comes out and chases the despicable orange cat away. That's good, but I can still see him for a while. That makes me angry. So if my humans try to get me inside I might hurt them. One of them has come up with some rather interesting ways of getting me inside.

Dogs
Dogs are stupid. Incredibly stupid. You know everything Garfield says about dogs? It's all true. Every single word of it. What's that? You want me to embellish? You don't believe me! *astonished but still cute* I guess if I must prove it to you... okay, dogs do tricks to please their masters. Cats can do tricks too — believe it or not. You just have to teach them. But cats know that they don't have to do tricks to please their owner(s). Cats have remained pretty much themselves since domestication. Cats were domesticated about 15 000 years after dogs. So cats still have a much of their original behaviours and instincts. Dogs don't. Cats are very independent. Just clean our litter box, give us food (so we are really healthy) and we can do the rest. Being a cat is a thankless job you know.