Worst Mobs Ever.

Also, Hitmen. Particularly Mook Hitmen. Not because they're hard, but because they're just freakin' annoying. I avoid Mooks because of them.

*Blam*
*run away*
well, I guess I'll wait for him to come back...
(2 minutes later) *Blam!*
*run away*
*sigh* Well, I guess I'll move on, I'm never gonna kill this guy without chasing...
*run to the next group, start the fight...*
*Blam*
sonofa...

Death Mages and Madness Mages. These are what grind an 8 man PUG posi TF to a crashing halt. 3 Death mages that get their dispersion bubbles on and you just as well reform and start again.

You can't hit them and their friends, you can't mez them and their friends, and they are simultaneously mezzing you and cutting you to ribbons with the ease of a hot knife through butter.

Worst mobs ever and they come packaged with all those nasty ghosts.

Some handy ways of dealing with some of the problem mobs:

Sorcerers: Kb/mez. Many sets have at least one of those. while getting up, they cannot port or do anything. mez shuts off toggles....if you can, use range. All of their debuffs effectively give them melee defense, but none elsewhere. Watch the debuff disappear with distance, then fire away. (If you can.)

CoT lieut ghosts: see above for debuffs. Though the invis/run away and heavy heal are nasty, this is their one true trick. Hitting them with a hold/stun/confuse eliminates this.

Vahz: covered this earlier, pulling is golden.

Longbow: they don't fare well vs. controls, though officers give unholy ammounts of confuse resistance. I find much of their AoE is placed, so aggro away from where you want to fight, leaving the sonic grenades and fire patches behind.

KoA: stun or kill them all. They all are troublesome. Un the other hand, going all-flight helps a lot.

PPD equalizers: glue patches give no -fly or -flyspeed. Raptor packs=win. Hate the acid mortar, though.

Malta: control/defense/-tohit. That's it; make sure stuff isn't hitting you. If you can't lock down the mobs consisting of TP'ing gunslingers and their unholy defense, operatives and their stacking alll-fight long duration stuns, the sappers and their bright blue energy vacuum, you will have a tough fight ahead of you.

Vanguard: controls/range. That's it.

Romans: controls, but do NOT use a stun/fear/sleep/hold on centurians. This cues a mass break free, making the entire group mez resistant. Confuse? not the case.

Nemesis: lieuts must die last. (Snipes as well.) Vigilance with it's +defense/damage/mez resistance is best left to when it only affets the last bit of health on a lone survivor.

Ascendants -- those stupid shield-toting "nyaa -nyaa - you can't touch me til I drop my folding shield" goons.

Also, the rooftop snipers in Founders Fall. My poor level 30 blasters ... trying to unlock their origin-based stores...
.

My most annoying mobs:

Longbow: One word: Nullifiers, with their sniper-ranged Slug power and their debuffs in the higher levels. Ballistas are also one of the few enemies I actually fear.

Rikti: Generally, they're not that bad. However, one of the nastiest things I've ever been faced with was a particularly large group composed primarily of a mixture of Guardians and Drones. Doesn't matter how good your accuracy is, when the Guardians manage to shield those damned things, as well as eachother, you're not hitting them. And things really get bad once they start popping AM. Need I also mention the constant heals?

Circle of Thorns: Spectral Demons, pure and simple. Ruin and Madness Mages I hate in the lower levels. Past 40 though, they're what I consider cuddly

Vahzilok: Vomit of doom, tranquilizer guns, and suicide bomber zombies. Need I say more?

Vanguard Sword: No explanation needed...

Cimerorans: The -Def makes my Bane Spider cry.

Rularuu: Observers. "Defense? What defense?"

Malta: While I consider the group relatively easy, I've been laid low by overlooked Sappers once in a great while.

PPD: Where to start... Equalizers with their Glue Grenades and Acid Mortars, Ghosts with their Flashbangs and Tear Gas, as well as the entire Kheldian division (which needs to die painfully in a fire as far as I'm concerned)

Knives of Artemis: Caltrops, duh. Also, the occasional and often lethal critcal hits inflicted by the bosses.

Red Caps: They hit relatively hard, plus they have a chance to change into a higher-ranked mob.

Tsoo: Yellow Ink Men are a particularly nasty wake-up call in the lower levels, and Sorcerers are, simply put, the most annoying mobs in the game.

Notable Individuals:

Lord Recluse: His channelgun attacks sap your endurance, plus he spam summons Bane Spiders when things get desperate for him.

Ghost Widow: Has a Mag ∞ Hold.

Statesman: Simply because his Unstoppable power recharges in (I think) 5 minutes.

Kadabra Kill: A Gravity/Kinetics/Empathy Controller. Not much more needs to be said.

If I don't have KB protection, Mook gunners annoy the crap out of me. They always run, then turn and use their KB laser. I finally get up and get over to them... and they run... Grr.

I have not played any lowbie clockwork content in years outside of synapse TF. The constant end drain at that level is mind numbing.

I would say at low levels, anything vahz Haas my vote.
mid level, CoT demon lords for sure.
High level, Malta with Rularuu bosses a close second.

I do want to pitch the KoA. These deliciously evil honeys do not get enough love. Where is the AV?....They deserve a more dedicated story arc or TF.....And at the very least a badge.

KoA are the primary reason I get my raptor pack from the first mayhem/safeguard mission.

Most of my obvious choices have been covered already: Spectrals Whatsits at low levels, low-level CoT bosses, and Malta, which seems to have been designed as a place to put all the "challenge" enemies that were left out of other factions. (I've long maintained, based on background and difficulty, that Malta should rarely or never fill entire missions; they should appear to support other groups, as they do in the mission in which they're introduced. But that's another discussion.)

Other enemies I can't stand include:

-Rikti drones. Impossible to hit and impossibly resistant to lethal damage.

-Arachnos drones. Excessively resistant to a common damage type, yet they spawn at a level when most attacks aren't well-enhanced.

-Mu at low levels. The endurance drain of these things is just brutal, pre-stamina. They also resist a fair number of damage types.

-Higher-level Consiglieres and the unique boss Kadabra Kill. In theory, these aren't especially challenging, as mid-level bosses go. However, all of them summon Singularities AND have their own Gravity Control powers. That makes it easy for them to stack holds. These enemies are some of the few that have wiped out my melee characters even without help.

Oddly, I generally don't hate Carnies. While they tend to phase a lot, they don't run away the way other phasing enemies tend to, or at least not as often, and it's possible to avoid their endurance drains. However, the real reason I like them is that they're one of the very few groups at high levels that isn't highly resistant to lethal damage (common to both my preferred AT's, scrappers and blasters). In fact, they're vulnerable to it! For high-defense Lethal characters with mez protection, Carnies are like xp-snacks.

Heh, I took a special kind of joy throwing blinding powder on Knives and confusing the lot of them to turn their massive caltrop fields against them on my stalker.

While folks have keyed in on the Cairns of the DE as a pain in the neck, and they are, I tend to find the DE Guardians and their Quartz eminators most annoying. Unless your survival is purely resist-based, ONE single Quartz sitting anywhere in the area and the team gets shredded like tissue paper. :P

It is notable that CoT start off horrible from the get-go, transition through semi-horrible, and end up relatively trivial in the end-game. Once you get past the spawn levels for spectrals and earth thorns things mellow out quite a bit.

I concur with most of the things mentioned thus far as being very ebil, and also with the assessment that it's ALL about the AT.

Ranged or melee, lockdown or stealth, defense or resist, there's something out there that has your number...big time.

However there are some mobs that honestly it doesn't matter what you are. They are either annoying or deadly or both...plain and simple.

In this category I put KoA. 'Trops/stun/webnades and +Perception along with a tendency to launch ambushes from half-way across the map... if I see a mission with Knives, I look for the fastest way to finish it. Some troller/dom types get off easier, but not always. Also Vanguard, for the reasons mentioned previously.