Horkers.
They're really ugly, fat, slow, easy to kill, and although territorial, usually neutral.
I always feel bad when I get too close to a Horker and initiate a battle, in which my companion insta-kills the Horker with a brutal sideways, head-severence.

Anyone else feel some sort of sympathy (possibly empathy if you're a computer hardened animal) when a battle accidentally engages with any neutral beings, on the Skyrim landscape? (Horses, Cows, Dogs, Chickens, Foxes, Deer, Elk, etc.)

No, not really. I've never initiated battle with horkers, but they have attacked me plenty of times. And chickens? Those little bugger will call the guard on you if they see you comitting a crime. They can even report their own murders! But if nobody else sees it, the bounty gets removed. Yol toor shul! Winner winner, chicken dinner.

I kill them with pleasure most of the time. Hunting makes me money and gets resources, those guys are just walking piles of resources if you ask me. Once I have enough stuff to stop caring I will usually just let them go, but that has more to do with a lack of usefulness then feeling guilty.

Anything that attacks me deserves a reprimand, be it verbally of fysical

"To kill or not to kill" that's not the question anymore, the question is: "How to kill?"

Giants... There they are, strolling around and herding their beloved mammoths, when suddenly in comes the Dovahkiin and kills them to level enchanting and alchemy... I dunno why, I don't mind killing other animals, but for some reason it bothers me to disturb the giant-mammoth-symbiosis:/

Maybe when I play a more evil-ish char it will be different, but with my current good-aligned one, I don't even kill bears, or sabre cats, if I can avoid it. I use the Kyne's Peace, and that's it. Only animal I kill are wolves, as long as I need to walk in their area. Else I just leave them be.

About horkers, never got attacked by one because I always keep my distance. Once I heard the combat music and I just walked away. It's their area (or home) and I'm the intruder.

Just a few days ago I killed a horse by mistake, and didn't feel good. There was a Spigran far away, so I took my bow and aimed at it, but it was just behind a horse, that was instakilled.

About sympathy? Well, giants are ones I respect. They are on their own bussiness, and only become agressive if you go too near. A few days ago I went to complete a quest give by a Jarl, to kill certain giant. I went there and I found the big guy on the fireplace, scratching his back, waiting for a cow to cook. I walked around with no reaction from him. I got nearer and he went into a defensive position, moving his club and telling me to back away, and all this without even attacking me. After a minute of threatening me with his club, keeping clear that I was invading his home, I decided to walk away and let him be. "Problematic giant that needs to be killed?". Nah.. I'm sure the 2 dead guys around the fireplace just went there to break his balls.

Anyway, things will be different with other chars I will play when I'm done with this one.

I tend to see Horkers as a bit of the landscape, and leave them alone.

I kill them for their meat and tusks. It's the circle of life

I never kill non-hostile animals, but Horkers are always violent to me, so I whack them and drain their health. But for rabbits, elk and others, nah. They don't have valuable fur, they're not hostile to me, so I let them live.

I kill the rabbits, ESPECIALLY THE RABBITS

It adds to my bunny death count in the in-game stats

If it moves, it dies.

What, there's a bunny death count?
Bye bye, gotta hunt some wabbits.

Lol, yes there is. I killed 6 or so? With my fists like a true hero. :] i try to kill the animals with only my fists. ^^

Anyway, as I'm playing with someone who's quite nature-minded and only kills an animal for food or when they attack me (without me intruding in their territory), I tend to leave them alone, sometimes sneaking my way past enemies (if I can't use Kyne's Peace on 'em). There have been instances where I had to kill spriggans who were obviously only defending their territory and the beasts who lived in there, and I felt kinda bad for them. Gave them a comparable "grave" to the ones I give innocent npc's who died because of me in some way.

I usually try to avoid killing animals because I don't want to disturb the eco system, but I will defend mysef.

I will kill horkers when I'm looking for cheap souls to fill my gems and increase my enchanting skill. Otherwise I leave them be. You have to be pretty close for them to become aggressive.

Animal Allegiance, Peace of Kyne.

Animals are there for our amusemant and their lives were only once created to give us the possiblity to end them. I started with killing deers, first for their lean meat and hardy hides. I still remember the look in the eyes of the first deer I butchered, his gaze meeting mine, I could feel him asking the question "why" as my freezing magic turned his body into a stiff carcass. I soon moved on to killing every animal I encountered, partly for the profit of doing so but mainly to simply display my power.
I am GOD, horkers are NOTHING.