From publisher blurb:
AN EPISODE FOR FOUR TO SIX WANDERERS IN THE ALMSFORD SETTING
The Leech King's cruel plot for Almsford is the same conspiracy he has imposed on innumerable planes before; domination by consumption.
The chthonic Leechspawn that comprise the King's masses are not unlike more familiar, mundane leeches; they are parasitic pests that drain the life out of those they manage to sink their teeth into. Unfortunately for a Leechspawn's victims, the similarity of affliction ends there. For one, while most common leeches are satisfied sucking blood on the exterior of their host, Leechspawn prefer to feed from within. While exsanguinating their prey from the inside, they'll also use its body as a breeding ground, multiplying their numbers and, over time, replacing most of the vessel's vital organs with their nests.
Through perpetuating this cycle of digestion and proliferation, the Leech King continues to heighten and expand its cosmic consciousness and physical presence throughout the multiverse. One can only surmise that the Leech King's ultimate goal is to continue his invasions until every sentient creature has become his meal and all possible intelligence has been assimilated into him.