Of all the greater servitors of the Outer Beings, few are as malevolent as the Greater Servitor of Yurrgh-Thal. Creations of Yurrgh-Thal himself, these loathsome creatures serve as his personal lieutenants whenever he sends his minions into battle. On several occasions, the greater servitors have served as proxies to their master, appearing before cabals of Outer Being worshippers and delivering his orders to them, as well as supervising important ceremonies.

These creatures are very large (roughly 12' tall and 20' long on average), and do not even remotely resemble any "normal" animal of any sort. They are vaguely slug-shaped, and a pinkish-grey in colour. Their "heads" are covered with dozens of pulsating tentacles, some tipped with red pupilless eyes, others ending with tooth-filled mouths or tendril-like feelers. Along the sides of their bodies are dozens of much longer tentacles (capable of stretching up to 20 feet), ending with serrated barbs. Their bodies themselves are covered by what looks like throbbing veins and arteries, and in several regions there are protuberances that twitch in a vaguely disturbing manner - these are in fact lesser organs, the loss of which does not hinder the greater servitor in any manner. As with many limbless creatures, greater servitors move by wriggling their forms, leaving a foul-smelling slime trail behind them, a particularly unpleasant sight.

Greater servitors of Yurrgh-Thal are cruel beings. They are highly wilful, serving Yurrgh-Thal out of fear of his power, but they gladly twist his commands in such a way that they can gain the greatest possible enjoyment from their tasks. If he ordered a prisoner to be brought to him alive, they would do so, but not necessarily in one piece. They consider humans, lesser servitors, and other such "short-lived" creatures to be inferior, worthy of little more than cannon fodder in wars, or of a passing source of amusement.

In combat, greater servitors show no mercy. They can attack up to four different opponents with their tentacles, but they can only use four of them at any one time. If a tentacle attack hits, roll for damage as above, but if a natural 19-20 is rolled, the tentacle's barb stabs into the victim, and several tiny spikes shoot outwards, doing an additional 1d4 damage. The spikes fold inwards at the end of that round, and the tentacle is withdrawn for another attack. Another attack favoured by these creatures is their spray of acid, similar to that of a black dragon, but far more concentrated. If a victim is hit, they may make a save vs. Dragon Breath for half damage. Otherwise, they will take 3d4 point of damage, and a further 1d6 points of damage each round thereafter unless they douse themselves with water, holy water, or have bless or remove curse cast upon them. This acidic spray can be up to 15' long and one foot wide. Finally, greater servitors are capable of casting clerical spells of up to 4th level, as many times per day as they wish.