Dendar the Night Serpent is a character in the Forgotten Realms campaign setting of the Dungeons & Dragons role-playing game. She is a giant and tyrannical extraplanar serpent that feeds upon the forgotten nightmares of mortals.
The Night Serpent's slit-pupil eyes are the sickly yellow-black of rotten eggs. Her forked tongue flickers incessantly over her smooth lips. Her monstrous fangs are always coated with the viscous essence of lost dreams. She speaks with a sibilant, malignant voice that drips with ancient horrors. Midnight-black scales cover her colossal hide and serve as the physical embodiment of the most terrifying nightmares she has swallowed.
Dendar the Night Serpent came into existence shortly after the first being slept and had a nightmare. She has an uncountable horde of horrible dreams and foul visions in her gullet that she has been devouring since the dawn of time. She relishes the taste of particularly choice nightmares and savors the dreams of kings and deities alike. More horrifying, if she did not feed her insatiable appetite, every being, mortal or deity, would remember every nightmare he or she has ever dreamed in excruciating detail. Supposedly, she will be the harbinger of the end of the world and even the gods themselves.
Although she can slither across the Barrens of Doom and Despair or any of the lower planes at will, the Night Serpent is almost always found in her lair. Dendar lives in a vast cave near the oozing river that surrounds much of the Fugue Plane. The hiss of the Night Serpent's breathing echoes through the plane as she sleeps, contentedly gorged on the world's unremembered nightmares. Anyone who approaches her cave finds her awake and awaiting them with anticipatory delight as she savors and relives their worst unremembered nightmares. Her cavernous maw is large enough to swallow a giant, and her tongue can knock an armored man to the ground with a single flick. Beneath her tongue is a foul mire of greasy spittle and half-devoured bones—the corporeal manifestations of her dream diet's remnants.
To the ancient Rus, Dendar was known as Nidhogg, the serpent who gnaws at the roots of the world tree that connects all things (Yggdrasil). In Calimport, she is known (incorrectly) as the Mother of the Night Parade. In the Jungles of Chult, Dendar is known as the Eater of the World. Legends tell of how Ubtao, Creator of Chult, will battle the Night Serpent when she emerges through a gigantic iron door located beneath one of the Peaks of Flame and attempts to eat the sun. If Ubtao fails in his duty, the stories say Dendar will readily devour the sun and the doom of the world will finally arrive.