Giant rats are just one of a variety of vermin that fill an ecological niche within dungeon complexes such as Stonehell. Living side by side with their smaller cousins, they may have evolved naturally to survive against competition with fierce predators, or they could have been deliberately or accidentally changed through magics. Whatever their origins, they’ve spread throughout the world and have established themselves firmly in the chain of life on the Coin.
Generally content to leave well enough alone, they will defend themselves, their nests and young, and their food fiercely if provoked. Sometimes they can be found in the service of other creatures, whether they have been tamed or not.