The Servants of the Terror were once men, enchanters and wizards. During the days of Entharion the Wise, when the Great Terror was aroused from its slumber, these seven did not wait to succumb to its horrible power, but instead sought the Terror out and gave themselves to it willingly, hoping somehow to forge an alliance with it and gain more knowledge and power for themselves. But the Terror enslaved them completely, took from them their wills and their natural human forms, and sent them out as Instruments of Fear. To do the Terror’s work they were able to assume whatever shape they desired after that, with the exception of that of men. They could never again become human. Together with its servants, it nearly destroyed all civilization. When Entharion the Wise imprisoned the Great Terror beneath Largoneth Castle, it finally returned to a deep sleep. The seven Servants of the Terror each slumbered along with it, hidden in their own treasure-filled lairs all across Zork, one of which was in uncivilized lands far north of Frobozz.

When the Terror was awoken and freed from Largoneth Castle in 956 GUE, the Servants finally awoke too, after generations to serve the Terror again. Deep underground in the woods around the house of Anesi and his family north of Frobozz was the resting place of one such servant. Nearby enchanters had always been able to spiritually sense it, even in its sleeping state. That was why the woods had always frightned Anesi. This Servant, taking on the form of a hellhound awoke, killing Fidget and his family, as well as Felbor, before it was defeated by Anesi. The other servants were aware of the death of their companion and headed north to seek out the murderer, but were unable to find him.

It was not until several days later when the six living servants, sensing Anesi's careless use of spells, found him at new Mareilon. The Servants took upon the forms of giant nabiz. Two went after Anesi in the inn, while the other four set out to ruin the city, seizing it with chaos. Though Anesi and his companions managed to escape, two of the servants demolished the tavern, smashing down the walls on three sides, while great swaths of wreckage marked the passage of the other four through the city. To destroy the nabiz within the city, Anesi casted RADNOG on the inn, defeating two of the Servants with the massive five. But the hungry flames spread to the next building and the next, until the entire city was aflame. Thus the second Mareilon died just like the first.

The four surviving servants would again confront Anesi and his companions at Dolo Finis, where the Terror also resided. These four servants, in bird form, were defeated by Chuck and nearly twenty other of his dragon kin.

Even in their sleeping states, enchanters were always able to spiritually sense the servants as waves of incredible fear, though it was doubtful that they would know what was the reason for their fright. While enchanters were able to sense them, so too could were the servants able to sense any magic used in the vicinity.

When one Servant was wounded, no matter the distance apart, all the rest would thrash as if they experienced the same pain, the same death as the others. Thus the others would know when one of their number was dead.

The Servants of the Terror could assume a variety of shapes, as long as they did not resemble anything human. While the most frequent guise seemed to be the shape of a giant black bird, they were also seen as hellhounds and nabiz. Whichever shape was assumed, it would always be far larger in size than the normal creature. This was because they thought an ugly form was scary, and a big ugly form to be scarier. It was their way of trying to instill fear. Like the bully on the block who is usually bigger than the other kids, they think of size as a weapon. They were stupid creatures, and had it not been for their size, they would have been useless. 

As a hellhound, the Servant was the largest, most ugliest of its kind. A giant, a monster, almost as large as a cottage. Its howl was more bone-chilling than the normal hellhound’s, augmented with a cold, knife-edged resonance that soared up and down an inhuman scale and would set even the leaves to shivering. With an extremely tough hide, it was impervious to arrows; they would sink into the beast’s side, hang there for a moment, then fall out without even an abrasion.

It is not certain if the form was of a corbie, but it was certain that this avian appearance was more frightening even than the hellhound. With tremendous wingspans, malevolent eyes that emanated hatred like a hot brand, and a peculiar whip-like motion their leathery pinions described as they pumped air, the passing shadows of these beasts instilled all they touched with an icy chill. As their huge leathery pinions pounded the air, each beat the air surged and swirled with serpentine lines of glimmering black energy that twisted and writhed wildly, shooting off at angles and accelerating back, where they wound and wound like weird mummy wrappings. Even from high above the earth, the Servants in this form were able to send forth this screaming wind to perilously bend trees as thick as a man’s body, crack limbs, ripple leaves free and slash them through the air. Wherever they went, a wake of destruction was cut through forests for as far as the eye could see.

With a wide yawning roar, the top of the Servant’s jaws, in the nabiz form, rose higher than a rooftop. Its flat, scaly forehead was used as a battering ram to break through doors and gates. By twisting its serpentine neck sideways it could grip entire building frames between its great teeth.

Each of these lairs were sealed up deep underground and hidden until the proper time of their awakening. While the location of only one has been recorded to have been discoveried, there is no doubt that six others exist. The one near Anesi's house, in the regions far north of Frobozz, was in the center of a forest, and filled with riches. There were wooden casks teemed with jewels and coins, necklaces and bracelets and brooches, weapons of fantastic craftsmanship, great and small swords and axes and shields, many draped with long, precious strands of pearls, and a great heap of diamonds and emeralds, rubies and sapphires, and amethysts twice as tall as a man and covering much of the floor.