I solo these often, and from what I've seen they drop an inky secretion 1 out of 4 times usually. I get the dark pages once in a while, and I had one drop a Pus-filled Ear (not sure what that is for, maybe just vendor junk). Gems are common off them, usually raw diamonds.
These are also a decent source of tainted essence for planer pottery, Trival at 216 for stuff you can make with it. Can also get some fluky runs with gems if you clear building enough times.
just for you wizzies (mainly), this is nice quad spot. 7 spawns in total. first pull is a 3 (just grab an outside foul pussie) and then second pull is a 4 =) . Have around 12000hp (at 62 with nothing uber - can finish vetri with 20-30m remaining) and i can normally do without med kiting. I find resist a lot less than vetri and i personally think slightly less adds.
drops raw diamond, blue diamond, etc (i think post below has).
First they do NOT drop parchments they do however once in a blue moon drop dark power pages along with assorted other loot type stuff
these do not cast root or dd spells someone is thinking of corrupted or wretched type puslings (wretched also summon)
they drop pages and diamonds ( not very often anymore )
loot list diamonds, raw diamonds, blue diamonds, pus filled ear, vail of pus, tainted planar essence, inky secretion, a chunk of unidentifyalbe bile, peridot, and dark power pages
Tried soloing these with swarm kiting. Its half and half on the ones you can charm. They cast root, 163DD and a mean DoT. Kill about 15 and got 2 Blue Diamonds and some other crapp