Old Hopshog is an impery that appears in Might and Magic: The Dreamwright and is mentioned in Might and Magic: The Shadowsmith. It was located in the Siccative, near the Aulmad. Like other imperies, it was made of black volcanic rock and constructed in concentric rings around the base of an ancient volcano. Its volcano was more active than the one Tustable was constructed around. The entrance gates were thirty foot high.
When Diligence's caravan was making its way to the Unseen Wall, one of their yeofolk became pregnant after being stung by an astilfe. The caravan headed to the nearest safe impery, which was Old Hopshog. Here, Grapple and the other yeofolk handler traded the pregnant yeofolk for two adult ones. When they returned to the caravan, the handlers had an air of aloofness, as if they were "ambassadors returned from a mysterious land".
While staying at the impery, Diligence decided to walk around and do a bit of exploring. She found a hidden passage in one of the walls, with a tunnel leading underground. She came across the yeofolk breeding pits, and watched the handlers taking care of the imps that were crawling forth. Heading deeper into the tunnels, she found an ancient room with an electronic plaque on the wall, and barely had time to hide before a strange creature entered the room.
The creature was large, wide-bodied and ponderous, moving with a slow, swaying, creaking gait that suggested that "its lower limbs were articulated in a radically different fashion from those of a human being". It was completely covered by a loose, purple-black cape. The size made Diligence think of yeofolk, but it had an unmistakeable aura of intelligence. It started pressing buttons on the plaque, and a wide doorway opened into one of the breeding pits. It snatched up one of the imps, and carried the squirming, squeaking thing into the lower tunnels.
When Diligence told Hitch what she had seen, he wondered if the creature ate the imps, and said that it was "like something from one of the Fabularies: a hideous monster under the ground, stealing babies for its supper and nobody knows".
This creature was one of the signs in the novels that the yeofolk were more than simple-minded herd animals, and it's possible that this would have been developed in the third, unfinished novel.