I remember my firstmeeting with a cliff racer. On the road to Balmora, desperately stabbing at it with a chitin spear.

I hate Cliffracers and Greater Bonewalkers.

To be honest. None. I actually think Morrowind has the best selection of enemies. A larger category of creatures, Daedra, it's the best.

Agreed

For me, it's usually Daedroths. The powerful Poisonbloom spell is enough to toast even a mid-level GCD character (a mid-level vanilla character should have the hitpoints to survive at least ONE attack), and they can recast several times. Trying to find cover that's far enough ahead of me to take the brunt of the spell and remain outside its radius of effect can be challenging, although they generally go down fairly quickly in melee combat. Obviously, my Argonian characters don't find them all that intimidating.......pfffft, WHAT spell?

Second is usually Trolls......in the MW forums, not in the MW game.

Oh, okay, I'll change my answer. I just didn't think about then earlier. Greater Bonewalkers with their dang Damage attacks! The only reason why I feel like buying Restore Strength and Endurance and Auriel knows what else. And this is pretty expensive for the new characters. Not to mention the confusion among new players must be big when they get permanently stuck or close to it. This never happened to me IIRC, although sometimes I had to abandon some good loot to get rid of the over-encumbrance. Then look for ways to recover.

(Now that I actually checked UESPWiki, the Greater Bonewalkers can only damage said Strength and Endurance, no other attributes... It will be cheaper from now on.)

You can make yourself an enchanted item to restore 1 point of Strength for 2 seconds, and just recast it several times until you can move again. I generally use a bracer or pauldron on my early-game armor, which don't hold enough of an enchantment to do much else anyway, but a ring or pair of trousers will work just as well. The skill requred to make such a weak enchantment hardly even requires taking the skill as a Minor, much less a Major, although the odds of success will obviously be higher if you do. A basic Rat soul in a Petty gem should allow for several castings, and will recharge itself over time; a "Cliffie" would be perfect for the job. It's only when enchantments start getting up into the 1/2 point and over category that you can't do them yourself at Level 1 without all sorts of enhancements and fortifications. Since the enchantment window only shows full points, you kind of have to "guesstimate" the casting cost. After that, Greater Bonewalkers are no big deal, just an inconvenience.

Kwama Foragers and Cliff Racers. Kwama Foragers just because they seem to be everywhere I need to go and Cliff Racers because there is just too much of an overabundance of them. I honestly wouldn't mind Cliff Racers that much if it didn't take them so long to fly downwards.

Cliff racers, hands down. I tend to run and ignore them until they 'pile up,' and then turn around and nail them with an AoE. Greater bonewalkers are irritating, but you can prepare for them. An enchanted item like above would be good, or you can do what I do, and create a spell that restores 10 pts. of every attribute. It's cheap, the mana cost isn't too bad, and your spell failure's not too high (generally). I tend to prefer this method because it's good for mitigating disease effects as well, and doesn't weigh anything.

There is nothing worse than having 350/0 Encumbrance because of those annoying bastards.

That they are, but with mods to vary the enemies it's not too much of a problem.

I once made a mod that sets their stat drains to be only five min instead of permanent damage. I called it Less Annoying Bonewalkers. I still left them somewhat annoying for game balance.

Cliff Racers. Good thing a mod kills any upon them appearing.