The Gutworm
unfathomably long, thick as an oak
Hides in the Rotblack Sludge beneath the Accursed Den. Can easily reach rooms 9, 12, and 15 of the den.
HP 50, Morale −, Thick hide −d6 Razor sharp teeth d10: Test Agility dr6 or be devoured, dying instantly.
Every swim through the sludge has a 1–2 on a d6 chance the Gutworm bites (d10 damage); test Agility dr6 when bitten to avoid being devoured and dying.
Lesdy believes consuming the sludge would let her control creatures like the Gutworm — but when she tries, the Gutworm attacks her on sight.
The Gutworm's age, origin, and the dimensions of "unfathomably long" are open. The deep caves beneath the sludge — where Lesdy wants to reach — are the Gutworm's natural territory; an extension of the Accursed Den downward would naturally encounter more of it (and more like it).