A Fiendwurm in Dungeons & Dragons is a terrifying and colossal creature, often associated with the lower planes and demonic realms. These monstrous serpents are born from the darkest pits of the abyss and are feared for their insatiable hunger and destructive capabilities.

Fiendwurms are enormous, with bodies stretching hundreds of feet in length and covered in thick, scaly hide that is nearly impervious to damage. Their scales are usually dark, ranging from deep crimson to pitch black, often glowing with infernal runes or patterns that pulse with demonic energy. They have massive, gaping maws filled with rows of razor-sharp teeth capable of crushing almost anything in their path.

These creatures are more than just physical powerhouses; they are infused with malevolent magic and possess a variety of supernatural abilities. Fiendwurms can breathe streams of hellfire or toxic fumes, capable of incinerating or poisoning entire groups of adventurers.