All cats have a sworn enemy, often, more than one. For my new kitty Boz, it is the pull chain on the ceiling fan. What about your kitty?
Please remember the immutable law of the Straight Dope when posting about your kitty.
Boz and his enemy. Boz and his sworn enemy - YouTube
Sneezes and vacuum cleaners. He’ll run and hide half the day from one and attack the other. I just wish it was the other way around…
Don’t worry, Boz. Very soon, you’ll be big enough to take down and destroy that nasty chain.
Keep striving and victory will be yours!
I haven’t had a cat for a while but I’m pretty sure all of the cats that ever lived with me had sworn to eventually kill every non-cat species of animal, every object or machine that did not serve it’s purpose, and all but selected members of the cat species as well. As long as I was feeding them I believe they would stick by their promise to kill me last.
In a couple of specific cases, my cat Bobby along with his friend the deaf white cat maintained an active campaign to kill all dogs, raccoons, and pretty much any other animals withing their range of travel, and my cat Lips had sworn to make the death of all moths a priority over his natural antipathy for any other small creature he encountered.
Charley and Emily used to get along nicely when they were kittens growing up, but about a year ago I brought home Annie.
I was a bit worried about how the older cats would get along with the new kitten, but Annie is a sweetie-pie. She gets along great with Emily. She even gets along with the more temperamental Charley. But since Annie came into the house, Charley has vehemently taken against Emily, and hisses, snarls, and growls when she sees her. I have to wonder what Emily said to Charley to suddenly make them arch-enemies.
The closest I have to “my cat” right now is Ms. Mousey, a freelance rodent-control contractor who works for my mom (she’s the one on the left). She gets along great with one of the other local freelance cats who we think is her brother, and pretty well with a third one, but whenever the next-door neighbor’s cat comes over, there’s always a fight.
We’re trying to train Bowser to only bark at that cat and leave the freelancers alone, but he doesn’t seem to grasp the distinction.
Oh, and Miss Mapp, make sure to keep the original packaging in case you ever need to send Annie back for servicing.
UFInsects.
Crows. Harley, the orange kitty, is bonkers about the crows (ravens?) around our house. He’s an indoor-only cat. We feed squirrels on our deck which is exciting enough, but when crows show up for leftovers or sometimes handouts, he paces, meows, barks, and runs into the glass door of the dining room which leads out to the deck. They ignore him. Upstairs, we have some cedars at window level about 20 feet away that the crows like to perch in while waiting for the handouts, so Harley has to sit in the window and bark at them. If one is walking on the roof, he can hear the tap-tapping and goes crazy running from window to window peering up trying to see them.
The other kitty, Twig, is very sweet and doesn’t have a war with anyone or anything.
I love that video of Boz! 
Thanks! I love your tabbies but had to work at it to see them. You might ask a mod to help with the link.
Coyotes.
We’ve been through about 100 cats, but this one we have now has defied the odds. I think it is because she is too skinny for even the coyotes to be interested. She’s about 7 ounces. Bag o’bones.
Reasonably friendly, as far as cats go. I haven’t had to kill her myself, yet. 
That’s really weird. It worked ok when I posted. Here’s another try.
The vet. Both of my boys hate her more than they hate water and the “no personal space” puppy.
Your original URL didn’t have .jpg at the end.
Haven’t got any pictures for this one. Sorry.
Maggie, the protectress of our daughter MilliCal, was so utterly alarmed when I put our stuffed gargoyle in front of her that she scratched the leg of Pepper Mill (where she was at the time). He hackles went up, her tail fluffed out, and her ears went back. Her back arched as she prepared to do battle with this fearsome foe that had suddenly appeared in our midst.
Except – none of us were paying it any attention. All three of us were oblivious to this toothed monster. Our other cat Midnight even came up behind it and rubbed against it.
Confused expression on Maggie’s face as her defenses slowly deflated and she gingerly approached the foe. I don’t think she ever figured it out.
Natasha’s mortal enemy is the dreaded cast boot. The ankle strap must be unthreaded from the loop at all times. This apparently is her prime directive and must immediately be done whenever she encounters the cast boot.
My cat hates the DVD player with a vengeance. It sucks things in, makes weird sounds, and spits stuff back out. He’ll bop the tray whenever it pops out, and sits patiently nearby until the tray opens again.
Allie doesn’t care for strangers to begin with, but especially hates one occasional visitor. They don’t interact, but The Princess is a hissy snarly little bitch for a day or two after this person, who does like cats, comes over.
Pandora’s sworn enemy is, ironically, the cat carrier. (As a wee kitten, she wouldn’t come out. Now she won’t go in. Well, she will if I leave it out, but the little witch is psychic and knows what day is vet day, even if the carrier has been out for months.)
I have to take her to the vet in a hamper with the top bungee-corded on.
Sebastian’s sworn enemy is late breakfast or dinner.
