Muglumps were large, deadly creatures that were frequently found inhabiting the Mire and, to a lesser extent, the Sewers of Undertown. They often posed a threat to creatures and convoys trying to cross the area to reach Undertown.
Muglumps were hideous beasts, with lumpy mound-shaped bodies covered in knobby white skin. They spent almost all of their time lying on their backs, pushing themselves through the mud with their six spindly legs. Their heads were dominated by two bulbous eyes, an inverted mouth filled with fangs, and two nostrils positioned on stalks. Their legs terminated in flat feet with four rapier-sharp claws, and their tails were covered with bony spikes and barbs.
Preying on anything that crossed their domain, muglumps moved underneath the surface of the mud, sliding stealthily toward their prey before bursting up and attacking with their characteristic "bone-scraping screech". They frequently hunted in packs.