Gargling Runt  

Yeah, you're bit off with this mob's level. Me and buddy of mine tangled with these just last night and they were white to him (lvl 40 paladin) and yellow to me (39 wizzy and unbeknownst to me soon to be 38). Some high levels came in and spawned the Gargantula and a gang of these runts while we were camping the AC while my friend had his 26 ranger out. Needless to say he was forced to zone and after conning these things, I decided to follow suit just to be safe.

He then logs on his paladin and we go back to clean these up one at a time. Two were waiting by the Oasis zone line so he shoots one and I standby to nuke. Well...either these things hate casters or they hate Erudites because the completely ignored the paladin and came right at me in a hurry. Nothing he did would pull them off me, whereupon I learned a couple things:
1) "Immune to changes in speed" read the message that popped up when I tried to root these puppies, so no root, no snare will work and...
2) They don't wander off when you zone; they'll sit and wait for you to return right at the spot they lost aggro on ya.
What's more, these things hit for 100+ so the first one that reached me blew right through my steelskin. Needless to say, I dropped rather quickly. And the nasty buggers sat on my corpse until the paladin drew them away! The paladin eventually soloed one, but he was at 6% life when it was over. Tenacious little bastards...
On the up side I got my ring of the ancients, making my loss of a level somewhat worth it.